[leroycash]

Good catch!

There are a few heads w/"ideal" specs for chamber volume, valve size, screw in studs, valve angle, etc. but expect to pay a premium for them when and if you find a set in good condition.

Personally I'd rather have a set of aftermarket heads than a stroker bottom end. Aluminum heads w/a set of aftermarket forged rods and a stock crank trumps iron D-ports and a stroker bottom end, IMHO.

Thanks, got ahead of myself there.

What is it about aftermarket heads that makes you say this? The prices I'm seeing are pretty high. I like the assurance of a new un-used unit for sure. The chamber sizes are nice and the machining seems super precise. Is it the improved airflow? I know we've come a long way over the last 35 years! Wondering if it makes sense for my street application.

Thanks again for your comments.

 

[leroycash]

The 400 has an advantage over 461 if higher revs and high-end HP are the goals. For a general rule for a street engine, "no replacement for displacement". The low-end power generated by the strokers is among the best of any engine family "out there". Base your decision on which 'type' of engine you want. The 400 will have a higher "fun factor", but a shorter life. The stroker will ROAST the tires "on command" and will live longer. A 4" stroke (ala 421, 428) offers "the best of both worlds", where it can safely rev, AND it generates significantly more low-end torque than 400. A 6.8" rod and a 4" stroke yields a "perfect" 1.7:1 rod/stroke ratio (same as Chevy 327). Our blown/alcohol 475 (4.350 x 4) shifted at 9,200. Yes, a real Pontiac... -
Jim

Thanks for the comparison. Am I getting you right, you're comparison is between two 400 builds. One with a smaller displacement (stock stroke) where the power is at a higher RPM, and the other is a 400 stroked to a higher displacement (say 4.25") where the power resides at lower RPMs? Is the lower RPM scenario more reliable due to lower revs? I guess that makes sense. And the 421/428 reference as being ideal is due to the fact that it has a "mildly" stroked displacement at 4.00" even. BTW I have access to a 428 short block for a good price. The problem is its been bored 0.060 over. That seems risky to me. How much bore is too much I wonder? Also, when you mention your blown 475 are you saying the bore is 4.35" and the stroke is 4"? If so, what block are you working with? Sounds like a 421/428 configuration. If so maybe a 0.060 over bore isn't so risky. Man, a 428 would be outside the box.
Thanks again for your comments.

 

[cobalt327]

Thanks, got ahead of myself there.

What is it about aftermarket heads that makes you say this? The prices I'm seeing are pretty high. I like the assurance of a new un-used unit for sure. The chamber sizes are nice and the machining seems super precise. Is it the improved airflow? I know we've come a long way over the last 35 years! Wondering if it makes sense for my street application.

Thanks again for your comments.

From my experience, the 400 or 455 engine displacement is adequate if not almost excessive in the case of the 455 from a torque-producing standpoint, for a street vehicle such as yours. Unless I miss my guess, a 455 w/proper machining and a ported set of D-port heads w/the correct CR for the cam being used will satisfy you 95% of the time.

Whether the added airflow (and yes- airflow is the root of why aftermarket heads are good) that can allow more power while using 'less' cam than might be otherwise needed if using iron D-ports would benefit you more than added displacement (displacement favors torque production all else being equal), is something we all have to weigh one against the other.

For a hot street/strip engine I could easily settle for a 400 or even a 455 w/good heads over a stroked 400 (or a 455) that was saddled w/iron D-port factory heads. Professionally ported iron heads- while being able to flow good, etc.- are not a bargain cost-wise compared to aftermarket aluminum heads either, IMO.

Be aware these are MY opinions; others may disagree w/all or part and that's fine, too.

 

[Mr. P-Body]

Let's "level-set" here. A 400 means it has the 3 3/4" stroke. The 3" main block is more desired because it's physically stronger. Though the aftermarket cranks are a little longer stroke than a "standard" 455, they're functionally the same thing. A "stroked" 400 (refered to as "461" in the Pontiac community) will act just like a 455 only tougher. Considering the price of a 455 core, and grinding the crank, you're better off (money-wise) to get a 400 block and a $300 Eagle cast crank (equal or better than the Pontiac nodular crank). The quality is excellent.

The crankshaft in the 428 is what you want. The 4" stroke, it's either a good nodular casting or "ArmaSteel", also a good casting. The mains get ground to 3" and the rods to 2.2", so if it's been ground before, it's no big deal. Ken's Speed and Machine in Brooksville, FL sells the correct thrust bearing "kit" that shims the large journal crank into the small journal block (100% reliable). Icon has the correct piston listed as "440 Pontiac", using the 6.8" rod. EXCELLENT combination. The 428 block is a paper weight if .060" over. Don't want it anyway, as it has the 3. 1/4" main.

Jim

 

[leroycash]

Whether the added airflow (and yes- airflow is the root of why aftermarket heads are good) that can allow more power while using 'less' cam than might be otherwise needed if using iron D-ports would benefit you more than added displacement (displacement favors torque production all else being equal), is something we all have to weigh one against the other.

Good stuff. I think I'm following you with respect to the argument you get plenty of displacement (more than I will probably need on the street) with a stock 400 without stroking to a higher displacement. And that dollar for dollar a good set of aftermarket heads - producing greater airflow - along with the correct cam translates to more (read, efficient) HP. Is this regardless of displacement? Or would you cam the larger (stroked) displacement differently regardless of whether you use aftermarket heads or cast D-ports? And, just so I know, where can I go to get the basics on cam selection. I don't know how to evaluate/talk about cams yet.

Thanks again.

 

[cobalt327]

Good stuff. I think I'm following you with respect to the argument you get plenty of displacement (more than I will probably need on the street) with a stock 400 without stroking to a higher displacement. And that dollar for dollar a good set of aftermarket heads - producing greater airflow - along with the correct cam translates to more (read, efficient) HP. Is this regardless of displacement?

Basically, yes. Regardless of displacement an efficient set of heads can make ANY engine better. Obviously an engine is a system, so all parts must harmonize to get the best results.

Or would you cam the larger (stroked) displacement differently regardless of whether you use aftermarket heads or cast D-ports? And, just so I know, where can I go to get the basics on cam selection. I don't know how to evaluate/talk about cams yet.

Thanks again.

You would need more cam w/less head to reach the same power as a good head. Pontiac heads mostly call for a split pattern cam. As far as where to get some knowledge of cam selection, I'd say to ask those who've BTDT- w/the combo you plan to use. I don't give specific cam advice (it's a boring story), so I'll leave that up to others and your own research.

The questions you pose (which are good ones, BTW) are things we all weigh, as I said before. In YOUR case, a 400 w/good heads would certainly be a ton o' fun. But so would a 455- even w/6X heads. I mean, you can get WAY over 500 ft/lbs. from a totally streetable 455 combo (even w/the 3-1/4" journals) that redlines at 5000 rpm- an rpm that allows a long life from the engine even when using stock bottom end castings. The engine I built on a shoestring back a few years ago used stock rods (*GASP*) w/nothing more than ARP bolts and resizing on a stock 455 crank turned 10/10. I've written about this particular engine many times here- not because it was a state-of-the-art piece, or because it could take down a BBC w/the blip of the throttle. I write about it because for the same money as a decently built SBC, I came up w/a true Pontiac engine w/a bare minimum of aftermarket part$ that propelled my '81 all-steel Camaro (>3600 lbs) w/3.31:1 rear gears to mid-12s w/ease. Hell, the car went 13-flat leaving the line from a dead idle and leaving the shifter in D and letting the tranny shift out at 4500 rpm! It needed only 34 degrees timing, never overheated and was daily driven for years w/o a whimper and I ran the hell out of it. I could have welded the hood shut on that engine, it was so reliable and understresssed.

In your case it really boils down to what you have available to you to work with (or are willing to find) as far as engine blocks, cranks, heads, etc., your budget, and your goals. I ran a 428 Pontiac way back in the '70s. It was a radically cammed, ported D-port headed animal. It was fast- but it was temperamental. I won a lot w/it, but I did a lot of maintenance to keep it sharp. It would NOT be something I'd recommend for your case- it's the wrong tool for the job. A milder 428 could be made to perform very good, even in your case- but I cannot recommend giving up any displacement (stroke particularly). To put it another way, if the build is going to be relatively mild, build it as large as practical. That could also be said even if the build was going to be radical, but I'm talking affordable streetable engines here.

Your '50 'Liner will have some weight. Most guys who build that style car aren't looking for ultimate 1/4 mile performance; they'd rather have a smooth, powerful engine that will tote the load w/o drama. So if you can "get by" w/13-flat 1/4 mile performance, a 455/D-port combo will do it. So would a 400 w/good heads, but at a higher rpm- meaning a lower rear ratio. It's all a balancing act and everything's a compromise to some extent.

I'm not much for spoon-feeding (not that you've asked to be spoon fed). It's one of those "teach a guy to fish" deals. But I think you can read between the lines enough to know what I would lean towards. Because of how/where I was raised I never spend frivolously. To say "I have X stroke aftermarket crank, w/Y-brand BBC rods!" means VERY little to me, unless these parts are actually needed to reach a particular goal. This holds true regardless of the make on the valve cover.

 

[leroycash]

The crankshaft in the 428 is what you want. The 4" stroke, it's either a good nodular casting or "ArmaSteel", also a good casting. The mains get ground to 3" and the rods to 2.2", so if it's been ground before, it's no big deal. Ken's Speed and Machine in Brooksville, FL sells the correct thrust bearing "kit" that shims the large journal crank into the small journal block (100% reliable). Icon has the correct piston listed as "440 Pontiac", using the 6.8" rod. EXCELLENT combination. The 428 block is a paper weight if .060" over. Don't want it anyway, as it has the 3. 1/4" main.

Jim

Okay, that was crystal-clear. Thanks. I understand the 461 pretty well and see several places that help with parts for this setup. The 428 crank option is interesting too. Seems like a good compromise, as you mentioned from an earlier post. Good displacement and revs. I spoke with the guy who has the 428 short block and he'll sell the crank for $125. I'm planning to look at it next week. I'm hunting down the Icon piston right now and will run some numbers to see what SCR it affords. I'm getting 9.15:1 with a 6cc KB piston and a 6X-4 head. None of the aftermarket heads hit the chamber displacement I need for this scenario. Still looking there too. So milling the 428 mains to 3" is no big deal given the quality of those original castings. I remember reading those castings were superior. This setup gets me to 433 cu.in.. I'm guessing this is known as a 440?!? One final question, if I can get my hands on a good 428 block is there some other concern you would have going with this vintage, and very cool setup? In the end performance and reliability trump cool.
Great reading your stuff.

 

[leroycash]

Your '50 'Liner will have some weight. Most guys who build that style car aren't looking for ultimate 1/4 mile performance; they'd rather have a smooth, powerful engine that will tote the load w/o drama. So if you can "get by" w/13-flat 1/4 mile performance, a 455/D-port combo will do it. So would a 400 w/good heads, but at a higher rpm- meaning a lower rear ratio. It's all a balancing act and everything's a compromise to some extent.

To say "I have X stroke aftermarket crank, w/Y-brand BBC rods!" means VERY little to me, unless these parts are actually needed to reach a particular goal. This holds true regardless of the make on the valve cover.

You're right, my 50 Streamliner will never shed enough pounds to run in the 12's (it's currently a 4,700 lb. slug). I bought it because of the Harley Earl lines and the fact that it's all original but far from show quality. I'm not going to shave or chop anything. From the curb it will look stock except for those unusually large diameter pipes hanging out the back. I'll keep the 50's era automotive history that matters to me while swapping out the driveline for a package that moves the car in convincing fashion. I want to put a Pontiac back in it for some reason. Better yet a not-so-standard Pontiac. I've gotta have torque. I wouldn't be ashamed of a rough idle. I've never had a hot rod with an automatic but could be convinced. My current plan is to track down a period correct 4-speed manual to go with the short block. Don't yet know about the gear ratio out back but want to be on the other side of the intersection before grabbing second gear. I know I need to pin down the rear end before I can make the cam selection. BTW what is the best argument for an automatic transmission? It seems everyone assumes you go with an automatic. I'm not planning on the car being a daily driver - but hopefully every other day. I'm sure there will be times when I really need to smoke the tires, if for no other reason than to hear the kids squealing in the back seat. It has to perform on the highway. I won't take it to the track. As for budget I can $plurge on a handful of things but overall it's a tight build. If I find a good quality 455 I pay a premium right off the bat, but get the huge displacement. That's a solid path. On the other hand there are plenty of 400's nearby to choose from. If I go this way I could have a block cleaned and inspected by the end of next week but will need something - maybe extreme, maybe not - to make up for the lower displacement. Something's gotta be lurking underneath that big hood. Why build you own mill unless there's something extraordinary about it. What's the goal? Google "1950 Pontiac Burnout. That's the goal.

 

[cobalt327]

Nothing wrong w/a 400 block and the now-affordable aftermarket cast 4.25" crank and decent rods, as has been mentioned already. That's if a rebuildable 455 core will set you back more than the sum of the parts to build a 400 into a stroker.

I wouldn't recommend a stock Muncie M20 behind the big Pontiac and 4700 lbs- along w/a relatively high rear ratio. That's just asking an awful lot from that transmission. The M22 "Rockcrusher" is somewhat stronger but it has close ratio gears (not needed or even wanted w/an engine having a wide powerband like most Pontiacs). Now there are aftermarket solutions to the strength issues of the Muncie. AutoGear has posted about the availability of different (stronger) Muncie gearsets and cases, etc. Then there are stronger manual transmissions (TKO, etc.), but these are costly. Pluses are OD and/or low first gear ratios.

The main reason behind using a TH400 is strength (it has plenty) vs. expense (not that much, even w/good soft parts and 34 element sprag, etc.). And setting up a vehicle for an AT is uber easy- no hydraulic TOB or Z-bars, no clutch pedal assemblies, etc. An AT can be easier on drivelines, too. Not as much fun, granted.

 

[MouseFink]

A 455 short block , any reasonably priced 1972 - 1979 cast iron heads you can find that are still in rebuildable condition, Summit K2800 hydraulic lifter camshaft, Edelbrock 2156 Performer intake w/o EGR, Rochester Q-jet , Pertronix D1200 Street/Strip HEI distributor and a well built TH400 is the only way to go for a part-timer using pump gas.

You will not regret it.

 

[cobalt327]

If you plan to use tube headers (which you should), avoid heads that haven't got the end holes to mount the headers or manifolds. One example is the 7K3 head. There are brackets that allow the use of headers, but the brackets are expensive and I don't know how they hold up. More here.

Avoid "shorty" or block hugger-type headers. Avoid 3-tube Pontiac headers. There have been guys saying that they make no real difference in performance- to this I say BS! The ONLY thing going for them is they're marginally easier to install in some apps, and they're generally cheaper. You can use cast iron RA-type manifolds, but for the cost difference- unless the fit was enough better to warrant them- I'd just as soon use headers. YMMV. Not that I need to bring in outside sources that have done back-to-back testing (like I did in the early 90s), but here is some testimony from someone else who saw a large drop in performance when using the 3-tube headers vs. 4-tube. Jim Hand is recognized as a legit source for Pontiac info that can be trusted. BTW the closer to stock the less dramatic the difference will be. More testing comparing Pontiac RA/HO manifolds, shorty headers, and long tube headers: Headers vs. Manifolds - High Performance Pontiac Magazine

 

[leroycash]

Nothing wrong w/a 400 block and the now-affordable aftermarket cast 4.25" crank and decent rods, as has been mentioned already. That's if a rebuildable 455 core will set you back more than the sum of the parts to build a 400 into a stroker.

The main reason behind using a TH400 is strength (it has plenty) vs. expense (not that much, even w/good soft parts and 34 element sprag, etc.). And setting up a vehicle for an AT is uber easy- no hydraulic TOB or Z-bars, no clutch pedal assemblies, etc. An AT can be easier on drivelines, too. Not as much fun, granted.

Thanks for the comments. Your right about the costs from what I'm finding associated with the two builds. The 455 build might even end up more cost effective given how little I would have to do to get decent performance. Finding a quality block of either displacement will set things in motion. I'm looking now.
As for the AT you make it sound so easy. I was looking at the TCI TH400 on the Summit website. Is this what you are referring to? Or is there a better place to look? I found an interesting rebuild source too. You're right about the manual hookup. It can be a bear with hydraulic slaves, action ratios and pedal clearances. I hadn't considered the weight of the body stressing the transmission and making it the weak link. Makes sense. I'm also looking into the beefier 4-speed retrofits as well. One thing that seems to come up with ATs is determining the correct stall. I don't know what that means. I read one account regarding a similar build setting up the TH400 AT with an 11 inch Hughes converter and 2500 RPM stall. You've got me scratching my head.
Hey, thanks again for your posts.

 

[cobalt327]

The newer TH400 sprag assembly are not as strong as the older TH400 tranny. The newer trannys started about 1971. The older trans (~pre-'71) had a smooth race on the hub and a true sprag whereas the newer TH400 got a "roller clutch"-type affair and a hub not compatible w/the 34 element sprag (see comparison below). Some info on the sprag can be seen here.

I would expect any aftermarket tranny to feature the 34 element sprag but it would be in your best interest to double check.

Undesirable clutch hub and dog clutch, left. Stock 16 element sprag, center. 34 element sprag and smooth hub, right.

The grooves cut into the dog clutch hub makes using a 34 element sprag impractical. The smooth type hub can use either the stock sprag or the stronger 34 element sprag- which is recommended for a high torque engine like yours.

Guys are now using parts from the 4L80 to upgrade the TH400 sprag assembly. You can research this if the need arises; a thread w/some info: http://www.hotrodders.com/forum/direct-drum-175248-2.html#post1248354.

Hopefully AutoGear will chime in on aftermarket solutions to the strength of the 4-speed Muncie boxes, as well as other options available to you for a manual box.

 

[AutoGear]

Greetings.

There are a few manual gearboxes you could look at.

A muncie style 4-speed with a supercase, iron midplate, roller bearing sidecover and the important part: Italian-made M22 style gearset, is available from a few sources. We use all of the above, and so do my authorized vendors. You'll be in the 2000-2300 dollar neighborhood for a complete gearbox. Our 'modular' design cluster gear would allow you to have a 2.98 or 2.56 1st gear, and several 2nd and 3rd gear options for either 1st gear. This means you could run a 3.08-3.55 rear gear and have a compact, very strong, hot rod 4speed.
I'd require a 26 spline input and I'd prefer a 32 spline output, but you could get by with a 27 spline output.
If you use a 27 spline output, it has 5 shifter mounting holes, where a 32 spline has only 3. Either way you're going to have to make a custom mounting plate to help get the shifter handle where you want it

To figure out your gearing; take the number 9 and divide it by the axle ratio you want to run. This will tell you the 1st gear ratio you should run in the gearbox. This reflects the performance of 60s and 70s high performance cars. (2.20 1st gear with 4.11s for example)

If it were me, Id use a 3.23 rear gear with a 2.98 1st gear. This gives you plenty of torque off the line to move the SS Bismarck, and a street friendly axle ratio.

You could use a TKO, Id opt for one with a .63 overdrive and gear the car with a 3.55 or similar.

You could use a Doug Nash or Richmond 5 speed, again Id run something like a 3.08 or 3.23 with a 1st gear in the 2.80 - 3.10 range or so

Id avoid a T10; the only ones you would be interested in would be the 2.88 and 3.42 1st gear with an iron case, and neither of these is strong enough for what you are trying.

Regarding automatics; I wouldn't look anywhere other than a stock 4L80e. Turbo 400 strength, with an overdrive. You will need an electric controller, but they're easy to hook up and it allows a LOT of adjustability.

If you're interested in a Muncie style 4 speed; I have a list of approved vendors.

 

[leroycash]

I would expect any aftermarket tranny to feature the 34 element sprag but it would be in your best interest to double check.

Guys are now using parts from the 4L80 to upgrade the TH400 sprag assembly. You can research this if the need arises; a thread w/some info: http://www.hotrodders.com/forum/direct-drum-175248-2.html#post1248354.

Hopefully AutoGear will chime in on aftermarket solutions to the strength of the 4-speed Muncie boxes, as well as other options available to you for a manual box.

Thanks for the crash course on the TH400. The links help a lot. I think I just doubled what I knew previously about ATs. There have been a few 4L80e cores I've noticed online but not many. I've rebuilt manual transmission but nothing as complex as a TH400. Not sure I'm ready for that. Was the 4L80e for towing and service vehicles? Maybe I could look there as well for a good core. I have to admit an AT has its advantages assuming I can find one that fits my build. Still, if I can shed a few more pounds off the Streamliner a stout Muncie 4-speed would be retro and fun. I'm going to think about this while I tackle the short block for a while. Thanks again for the links.

 

[cobalt327]

The 4L80E would be found where a TH400 would have been previously. Heavy duty 1500 to 3500 series trucks and like that. One downside is no provision for a mechanical speedo, and another is they ordinarily need a control box to operate w/o the original vehicle computer, although full manual valve bodies are available that need no computer.

And the 4L80 is BIG! You can look into a 700R4, it's not as heavy duty stock but can be built to be durable. Another AT option is a TH400 w/a Gear Vendors OD attached to it.

I agree a manual would be choice in your car, though.

 

[leroycash]

A muncie style 4-speed with a supercase, iron midplate, roller bearing sidecover and the important part: Italian-made M22 style gearset, is available from a few sources. We use all of the above, and so do my authorized vendors. You'll be in the 2000-2300 dollar neighborhood for a complete gearbox. Our 'modular' design cluster gear would allow you to have a 2.98 or 2.56 1st gear, and several 2nd and 3rd gear options for either 1st gear. This means you could run a 3.08-3.55 rear gear and have a compact, very strong, hot rod 4speed.
I'd require a 26 spline input and I'd prefer a 32 spline output, but you could get by with a 27 spline output.
If you use a 27 spline output, it has 5 shifter mounting holes, where a 32 spline has only 3. Either way you're going to have to make a custom mounting plate to help get the shifter handle where you want it

To figure out your gearing; take the number 9 and divide it by the axle ratio you want to run. This will tell you the 1st gear ratio you should run in the gearbox. This reflects the performance of 60s and 70s high performance cars. (2.20 1st gear with 4.11s for example)

If it were me, Id use a 3.23 rear gear with a 2.98 1st gear. This gives you plenty of torque off the line to move the SS Bismarck, and a street friendly axle ratio.

If you're interested in a Muncie style 4 speed; I have a list of approved vendors.

Hey Thanks for chiming in. I'm digging the muncie 4-speed option and your gear sets and cases make it look more possible than I realized. Not a typical direction to take with an early 50's hot rod. So I have a couple questions though, with a little more digging, I may be able to answer them myself. First, what's the main difference between the M20, M21 and M22 gear sets? From outward appearance they look identical. Is it the alloy? The machining? Or do they differ in a more fundamental way? They all look to be quality parts from the photos I've seen. Second, I didn't realize the Muncie was a side loader. I'm more familiar with the Tremec configuration with the various top-loaded shifters. You mention the 27 and 32 spline outputs set up different mounting holes for shifter positions. Where can I go to find out more on setting up the shifter geometry? I'm kinda partial to the original bench seat and the typical muncie shifter position is far back in the tail of the 32 spline extension housing. Not a deal killer but this changes my plan a little. Not to worried about fabbing my own mounting plate I just don't know enough about the geometry yet. Finally, bell housings. Any recommendations there?
Thanks again for your help. I looked at Riverside Gear and they have a lot of good parts to build from. Any chance you have a vendor in Texas?

 

[AutoGear]

I'd call Larry at Wells Speed in Weatherford TX. Theres also 'Kajun' Jon Bergeron in Whitney, TX.

I can send you a measured drawing of both versions of the aftermarket 'Muncie' (10/27 spline and 26/32 spline)

If you compare a factory Muncie to an aftermarket version, the aftermarket version is .147" of an inch longer due to the thicker front wall of the Supercase. This will push the trans back 147-thousandths on the crossmember. Your driveshaft slipyoke will normally handle this in a factory installation. I suspect you don't have a D/S so its not an issue. Comparing the 27 spline to the 32 spline, the 32 spline unit (factory or aftermarket) is .700 longer than its 27 spline counterpart. This is where people get screwed when they switch from 27 to 32 splines. It moves the shifter (possibly back or possibly forward .700" ; it also probably means your D/S needs to be shortened and the yoke changed AND rebalanced. If you go from a 27 spline factory to a 32 spline aftermarket; then you have to remember that extra .147" from the Supercase.

With regards to the Shifter, Id go 27 Spline mainshaft, this will give you 2 mounting patterns for the shifter block which will be about 700-thou ahead and 700-thou behind the 32 spline mounting location. I bet a 55-chevy benchseat "Bullnose" type handle would help; or buy the shifter and make your own handle out of stainless or aluminum barstock. Older Hurst shifters and linkages are OK; I've had some reports of the newer offshore made ones having linkage rods that are bent wrong and soft LOL
Buy and old one and then find the right handle, buy the handle new

Bellhousings:
A GM Bellhousing will work; you should still use a dial indicator to make sure the trans is mounted parallel to the block face and that the crank and input are inline. For a performance application; .005" TIR or less is preferred. For a street car, you can bump that up to .009 TIR.
If you want a scattershield, I really like the Quicktime. But its twice the price of the Lakewood stuff; twice the quality and probably half the weight. If you need dowel pins for adjusting the BH; look into a company called "Robb MC"

Gears: Lets get historical for a moment. The Muncie was introduced in 1963, but that was a far cry from what everyone is used to, its more Muncie 3 speed than anything else. so 1964, the Muncie comes out. The original design was the 'M21' close ratio (2.20 1st/ 1.64 2nd/ 1.27 3rd and 1:1 4th) and was designed for ROAD RACING not DRAG. This had a 7/8th" dia. countershaft 'pin'. Then the M20 was up; similar trans with a wider ratio spread using a 2.5 1st gear. The M20/21 use the same mainshaft gears, just a different input gear and cluster gear. Around 1965; the M22 starts showing up. This is a Heavy Duty version of the M21. M22s have identical ratios, but use a different pitch to the teeth than the 20/21. By todays standards, the M20 would be a close ratio; so 'close' v. 'wide' is usually a moot point in most applications.
Around 1966 the geartrain was upgraded with a 1" countershaft and synchro rings that have a support shoulder in them. This applied to ALL three ratios.
1970 we see the use of the 32 spline (Turbo 400) output and the stronger 26 spline input gear. This was ACROSS THE BOARD; *NOT* M22-specific.

The high quality gears are M22 design. The Italian ones are made of the European equivalent of 8620 steel. The firm that makes the Italian gears is Masiero, their parent company is Euroricambi. They also make the gun-drilled mainshafts (from the front, in the green state, and then hardened) and the
hardened hubs and sliders with select 'fits.'

You can convert an M20 to an M22 with a new gearset AND a M22-specific reverse front idler gear. The mainshaft reverse and rear idler are used across the board.

You may see high-end units with a multi-piece cluster gear; its essentially a splined shaft that you press fit 3rd and 4th on and hold in place with din-style snaprings. This is a part of the 'M23' Program (Severe Duty) which is proprietary to us and certain distributors, but I don't want this to be an advertisement, so PM me if you want more specifics on that.

Some guys use "house brand" gears or Indian/Chinese made M22 copies. They have a M22 ratio and an M22Wide ratio. Their M22W ratio is a 2.52/1.88 1st and 2nd gear. The Italian ones are 2.56 and 1.75 for 1st and 2nd. Im not saying the Chinese stuff is bad, usually its 'okay', but don't pay premium price for Chinese stuff. I hate seeing people get screwed. If you have any question about who carries the Italian stuff, by all means ask me privately. Hell I have Asian-made gears in an M20; they look better than the factory stuff did. But, its a crap-shoot.

An aftermarket Muncie with the Euroricambi gearset and a 26 spline input is perfectly happy behind a 502/502 ZZ502 BBC. If you are going to get rough with it, I'd go 32 spline output, shifter handle be damned. If you want to try and run with the big dogs, an M23 takes up where the M22-based stuff leaves off. An M22-based, italian gearset, aftermarket 'Muncie', with the roller sidecover, iron midplate, Supercase, Super Tailhousing and 26 spline input and 27 spline output weighs about 85 pounds dry and takes 1-qt of 75w90 non-synth GL4.

 

[leroycash]

And the 4L80 is BIG! You can look into a 700R4, it's not as heavy duty stock but can be built to be durable. Another AT option is a TH400 w/a Gear Vendors OD attached to it.

I agree a manual would be choice in your car, though.

Thanks for simplifying the AT option. I think a TH400 will stay in the running. I'll let a few more issues shake out before making a final decision about transmissions. Just so I'm clear, you still believe a TH400 with the 34 element sprag can handle the tonnage, right? Or would you lean toward the 4L80 given the current 4,600-lb weight of the Streamliner? I can always try to shave more weight somewhere inconspicuous on the car. After all it's gotta "look" slow (I mean, original) to be a sleeper, right?
Thanks again.

 

[cobalt327]

Thanks for simplifying the AT option. I think a TH400 will stay in the running. I'll let a few more issues shake out before making a final decision about transmissions. Just so I'm clear, you still believe a TH400 with the 34 element sprag can handle the tonnage, right? Or would you lean toward the 4L80 given the current 4,600-lb weight of the Streamliner? I can always try to shave more weight somewhere inconspicuous on the car. After all it's gotta "look" slow (I mean, original) to be a sleeper, right?
Thanks again.

The TH400 is equal to the 4L80, at least 75% of the parts interchange or so I'm told. Either can handle the load of your vehicle and engine combo. They both are/were used in the same applications- trucks w/large load capacity and curb weight. So there's no real strength advantage one over the other. That the 4L80 has OD is its biggest asset IMHO.