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That computes.
goofy size for a 74 Nova.
Factory tires would be over an inch taller.
cheapest way to reduce rpm would be taller tires.
Room for 28 inch tall tires.
 

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More for Less Racer
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24.4" tire and 4.10 gears is almost 3400 rpm @ 60 mph.....3389 rpm according to the calculator.

That's more than just a "hair over 3k rpm".

Sounds like maybe you need to investigate a little further....actually measure your tire diameter, actually check the rear gear ratio so you know where you are starting from? Because either the tire diameter or the rear gearing doesn't match up to the rpm you are claiming.

Have you joined Steve's Nova site??....you'll find a lot of specific info for the X-body overthere in the forums
(10) Chevy Nova Forum (stevesnovasite.com).
Or found Nova Resource?
www.novaresource.org

As far as the 5-speed, the new Tremec TKX is a less bulky external shape case version of the TKO, aimed directly at the "replace a vintage 4-speed" swap .
You won't have to cut the car, other than maybe a more appropriate shifter hole in the floor.....the 3rd Gen X-body has a pretty roomy trans tunnel compared to other GM cars like the Chevelle or Corvette.
You'll need to have a 26 spline clutch disc if you don't already(stock '74 Muncie would be)
 

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Discussion Starter · #23 ·
That computes.
goofy size for a 74 Nova.
Factory tires would be over an inch taller.
cheapest way to reduce rpm would be taller tires.
Room for 28 inch tall tires.
I'm with you there, but 1) The tires are almost new. 2) There is only about an inch to safely increase the tires and 3) an inch taller tires will only marginally help with that crazy RPM. I fear I my options are either to leave it alone or swap the tranny.
 

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Discussion Starter · #24 ·
24.4" tire and 4.10 gears is almost 3400 rpm @ 60 mph.....3389 rpm according to the calculator.

That's more than just a "hair over 3k rpm".

Sounds like maybe you need to investigate a little further....actually measure your tire diameter, actually check the rear gear ratio so you know where you are starting from? Because either the tire diameter or the rear gearing doesn't match up to the rpm you are claiming.

Have you joined Steve's Nova site??....you'll find a lot of specific info for the X-body overthere in the forums
(10) Chevy Nova Forum (stevesnovasite.com).
Or found Nova Resource?
www.novaresource.org

As far as the 5-speed, the new Tremec TKX is a less bulky external shape case version of the TKO, aimed directly at the "replace a vintage 4-speed" swap .
You won't have to cut the car, other than maybe a more appropriate shifter hole in the floor.....the 3rd Gen X-body has a pretty roomy trans tunnel compared to other GM cars like the Chevelle or Corvette.
You'll need to have a 26 spline clutch disc if you don't already(stock '74 Muncie would be)
Appreciate the info. And you're right, based on the calculator, my ratio should be 3.73. Gotta dig in there I guess.
 

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I’m with the TKX crowd, if money isn’t a constraint the shortest distance from where your at to cruising at an RPM that allows conversation is an overdrive.

A five speed stick is way higher on my fun quotient than a 4 speed automatic even though that’s what I have in my daily driver. With your cam an automatic gets you into a higher stall converter which quickly goes beyond simple oil cooling using the radiator heat exchanger, especially if you live in hot, hilly country or need to suffer through hot slow to stop and go traffic. Plus like I ment to say, there’s nothing like listening to a manual gearbox winding through the gears.

Bogie
 

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I run a set of 3.42 rear gears in my chevy s10 and I cruise around 2300 rpm at 55 mph and if my truck had anything less then that it would just be a plain dog on the bottom end and also mid range on things. I am running a turbo 350 so I have no overdrive. When I got my truck it had a stock 350 vortec in it along with a 700r4 and the rear gears were on the steeper side at around 4.10 and with the overdrive it cruised around the same rpm in overdrive.

My camshaft is nothing radical by any means and is only 268/272 220/[email protected] 510/510 lift with a 114 lsa and does pretty well for what my truck is setup with.

When I took out the 700r4 to put in the th350, I knew I would want to keep a similar rpm range to go with my engine build which is no stocker by any means and I knew I would need the proper gearing. So I did the math and also went by my other s10 v8 swap that I used to have and came up with the 3.42 ratio.

I run stock factory size tires as far as height goes around maybe 28 inches and came up with the range of rpm's I needed to keep my engine in the happy range for cruising wise. Any performance cam in the 210 @50 or more on the intake and 215 @50 or more on the exhaust will want at least low 2000 rpm at 55 mph to be within its starting torque range to make the build run happy and be able to give you what you want. The more duration the cam has the more the rpms move up and the more steep the rear gears will need to be numerically higher to get said build to run well.

That is the thing with performance stuff you can't always have one thing without sacrificing something else in return.
 

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This is pretty much the conclusion I have drawn after reading everyone's take. Especially this part: "If you take the short term view and stick with the four speed you will be miserable driving it no matter which gear ratio you choose."

To be frank, I am not concerned about the cost of a new transmission. My primary concern lies with opening a can of worms by trying to fit it in. Has anybody installed a Tremec on a Nova? I am assuming I need to purchase a kit (with the tranny, driveshaft etc.), correct?
There is a Tremec TKO and a newer version called a TKX. The TKX shifts better at higher rpms and both are available in 500 or 600 lbs/ft torque ratings. With your high numerical gearing I would go with the 600 lbs/ft. Its basically the first gear ratio that decides the rating and you don't need a lower first gear (500 lbs/ft). The TKX was designed from the beginning to fit in cars as a direct replacement for OEM transmissions. Clutch and bellhousing should work with no change, although I would check the bellhousing to see if the mounting hole is the correct size and is concentric with the crankshaft. Chevy trucks had larger bellhousing holes than passenger cars early on. Some people unknowingly used those housings when putting manual transmissions in cars. You can buy a spacer ring that slips into the hole and makes it the correct size if need be, but basically the transmission should bolt right in and need no changes. Note: There are several overdrive ratios to choose from. Call the phone number on the site below and ask for a catalog and any questions you might have. (No, I am not affiliated with them. I bought both my Tremecs from Summit Racing)

Might look here for info.

 

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235/40r17 is only 24.40 inches.

With that tire size(24.40") a 3.42 ratio puts you at 65mph at 3000rpm.

3.08 puts you at 2969 at 70mph.

So I am guessing you have a 3.08 ratio currently.

You can check the ratio by turning the rear tire and watching the pinion. It should be easy enough to tell the diffrence between 2.75 (2.73), 3(3.08), 3.5(3.42 or maybe 3.55), 3.75(3.73), or 4(4.11) turns.

I would just run the thing.
If I changed ratios it would be to 4.11's and eat the additional wear/reduced mileage. 3962 at 70mph. But like I said if your engine is built to run that then I have no issue running it. I may want to run a larger diameter tire size for long trips. But for daily driving I would be happy running that size.
Here is a nova site talking about tire fulfillment.
 

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This is pretty much the conclusion I have drawn after reading everyone's take. Especially this part: "If you take the short term view and stick with the four speed you will be miserable driving it no matter which gear ratio you choose."

To be frank, I am not concerned about the cost of a new transmission. My primary concern lies with opening a can of worms by trying to fit it in. Has anybody installed a Tremec on a Nova? I am assuming I need to purchase a kit (with the tranny, driveshaft etc.), correct?
Have you thought about calling Tremec or Richmond service or customer care and asking them about the conversion. They likely have a wealth of info to help you. I have a 72 C10 with a BBC tied to a 700 R4 and with a 3.73 rear gearing. It floats along at 2000 rpm at 70 mph on 18 inch rims with I think 265/60R18 tires. So not huge tires on a lowered truck but rpms on highway is great. The low gear on the 700R4 is so low that it shifts almost immediately into second (maybe 5 to 7 mph). Hits third at 22mph and shifts into 4th at 42mph. Only downside it that the shift into 4th is certainly no close-ratio shift, lol! Going from 1:1 to 1:0.63 is a true overdrive shift. But with the low first gear, you can burn all the rubber and money you want at any take off time.
 

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A five speed or a Gear Vendors OD (which is a bit pricey) is the best choice. 3.55 gears were common with four speeds back in the day. I'm mostly an AMC guy, and that's what they sold the AMX, Javelin, and SC/Rambler four speeds with stock. There were optional lower gears, of course. 3.42-3.55 should be a good compromise, but won't get you where you really want to be.

Be careful about comparing to auto trannys!! Auto trannys usually have less gear to get close to the same performance as a stick. That Javelin with 3.55 gears and a four speed stick would have 3.15 gears with an auto and feel close to the same in first taking off. Torque converters multiply engine torque. Old style stock converters multiply at 2:1 or more, so an engine with 300 ft/lbs of torque feels like a stick shift with nearly 600 ft/lbs. Late model converters are more efficient, and may be as little a 1.25:1. I know the stock Jeep AW4 converter behind my modified 1989 4.0L straight six is only 1.4:1.
 

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I once had this combo:

55 Chevy car
mild 327
Muncie M20
3.42 gears
27.4" tires.

Have to say it was no fun above 60 mph. Can't imagine what it's like with your setup. And it's hard to believe that back in the day 3.42 gears were very common behind 327s and 350s, with even shorter tires. Maybe the 60mph speed limit helped.

Had I kept the car, I would have gone with Autogear's M22Z with 2.98 1st gear along with 3.08 gears in its 8.2" 10-bolt. Depending on the vehicle, a Tremec TKO can be a real PITA to install because of its height. Been there, done that.
 

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I just did a set up for a guy with a setup like 55_327 mentioned.
69 chevelle, 496 crate engine, 3.08 rear gear in a "slightly narrowed" 12 bolt. 26-spline input, 32 spline output; to replace a peanut-port 454, 71-74 M21 and 4.11s. Gear ratios are 2.99/1.88/1.35/1.00
He was able to re-use his slipyoke/driveshaft, shifter/linkage, crossmember, pressure plate, console and shifter hole. At the track, plans to shift at 5500rpm and hes hoping to be in the 11s or more. No idea if he will have it sorted out enough to get there consistently, or how good of a driver he is...but there are guys who do this.
68mph is 2500rpm or so. Easy to tune the carb for that, and a single downshift will put him around 3900rpm which will put ~450ft/lb on tap according to blueprints dyno chart (after the typical driveline loss).
Different horses for different courses.
 

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When the normal selection of 4 speeds were introduced in the fifties and sixties, speed limits were 55mph or so. That won't even work in the slow lane these days. Add to that the fact that many soccer moms are driving vehicles with 4 cylinder engines that will out accelerate many 1950/60 "hot" rods, and a builder who doesn't gear properly is setting themselves up for embarrassment. While many of the engines are technically advanced, one of the biggest factors in their performance is "gearing". Factories leared that increasing the number of gears in the trans not only provided better gas mileage, but much better performance. With the larger engine preference of American hot rodders, not as many intermediate gears are needed. Simply adding one overdrive gear to a transmission virtually transforms it from a limited cruiser into an enjoyable commuter..........at no loss in performance. Its the logical choice for someone who wants performance and an enjoyable commute. :)
 

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With all due respect, it pays dividends to accept that there are customers/applications that can be sensitive to situations like: the loss in torque when driving through an O/D, the noise generated when driving through an OD, the weaker synchronizer necessitated by conventional OD ratios. And thats just the OD. Many people are sold on a starting-line-ratio that can be easily north of 12:1 (which is similar in scope to a close ratio trans with over a 5.38 ring/pinion combo). Some of these situations result in a driver who skips 1st gear all together and just starts in 2nd (1.90 or so). 1.90 x 4.11 is 7.80, which is catagorically unacceptable for take off. It will shorten the life of the clutch disc and flywheel. A 5 speed OD isnt the only answer; its simply a preference. Shift-ability of heavier 5spd geartrains, centerline shifters with weird looking offset shifters and isolator bushings; MAY create a driving experience
in 1st thru 4th, that isnt worth the OD cruising RPM. Sometimes its better to get 80-90% of the max cruising RPM with maximum enjoyment in 1st - 4th, not to mention a lower installed cost and changing less parts. There are also people who are sensitive to the idea of a non-american/european transmission in their car, or the high expense of repair parts.
People should take ALL this into account before plunking down ~2000 dollars for ANY transmission.
 

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‘Twas mine I’d lever her alone!
How do you know the rear gear ratio?
Did you pop the cover off and check the gears and numbers or did you turn one wheel and count the driveshaft turns.
reason I ask is your info of 25 inch tires, 60 mph and 3000 rpm computes to a 3.73 gear.
Are you positive you’ve got a 4.10 gear?
Side note: Both the 3.73 and 4.10 have the same tooth count on the ring gear. Pinion on 4.10 is 10 teeth. 3:73 is 11 tooth count.
 

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Discussion Starter · #36 ·
24.4" tire and 4.10 gears is almost 3400 rpm @ 60 mph.....3389 rpm according to the calculator.

That's more than just a "hair over 3k rpm".

Sounds like maybe you need to investigate a little further....actually measure your tire diameter, actually check the rear gear ratio so you know where you are starting from? Because either the tire diameter or the rear gearing doesn't match up to the rpm you are claiming.

Have you joined Steve's Nova site??....you'll find a lot of specific info for the X-body overthere in the forums
(10) Chevy Nova Forum (stevesnovasite.com).
Or found Nova Resource?
www.novaresource.org

As far as the 5-speed, the new Tremec TKX is a less bulky external shape case version of the TKO, aimed directly at the "replace a vintage 4-speed" swap .
You won't have to cut the car, other than maybe a more appropriate shifter hole in the floor.....the 3rd Gen X-body has a pretty roomy trans tunnel compared to other GM cars like the Chevelle or Corvette.
You'll need to have a 26 spline clutch disc if you don't already(stock '74 Muncie would be)
Yep, you were right. Did a manual count and the ratio is 3.73. can't help but wonder what other info the previous guy gave me is incorrect.

Anyway, a Tremec TKX with the 0.68 overdrive ratio should in theory bring me down to right about 2k rpm @ 60mph and about 2600 rpm @ 75 mph. And that's with the current tire size. This I can live with. Tremec TKX it is I guess.
 

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you might like it but your motor might not.
Easy test.
Go for a drive at 40 mph. In 4th gear. You’ll be turning about 2000 rpm. Just about the same rpm as at 60 with an overdrive.
See how your motor likes that.
I bet it’ll feel like a total dawg.
 

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Discussion Starter · #38 ·
you might like it but your motor might not.
Easy test.
Go for a drive at 40 mph. In 4th gear. You’ll be turning about 2000 rpm. Just about the same rpm as at 60 with an overdrive.
See how your motor likes that.
I bet it’ll feel like a total dawg.
I'm with you there, 2k rpm is still rather high but I think it's a good compromise between being able to cruise at higher speeds and still be able to go 0 to 60 in a respectable time. I could gear it down to 3.23 or something and get it real comfortable at higher speeds, but the down sides are well documented there. Since it's not a daily driver or anything like that, I figured 3.73 with .68 overdrive would be a good option.

With that said, it's not a stock 350. I do have a pretty rowdy cam so I wonder if it would make up some power if I go with a lower gear ratio. Do you have an opinion on that?
 

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like I said before in post #17.
‘Twas mine, I’d leave her alone!
A 3.73 is the best compromise ratio with your Muncie. Easy to get her rolling from a stop without out a lot of clutch finesse and still have reasonable rpm at highway speeds.
your 350 likely hits it’s sweet spot near 2600 rpm.
‘It’ll live at 3000 rpm for miles and miles.
IMHO not worth a trans or rear gear swap.
 

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Go with the TKX. You'll love cruising around with a lot less engine/exhaust noise.
 
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