As a start, Putting the truck on a diet to reduce weight would'nt hurt it none. As my dad would say, you're asking a lot out of a motor to pull that load,

Edit: You need to know you're SCR and its not to late to do the math. Plenty of calculators online out there,

 

Used standard Fel Pro head gasket.
Holley 670 Street Avenger.

Wallace calculator says 265 hp. Makes no sense to me, your choice of parts should make more power than that. Please post the specs on the head gasket. Never used a Holley 670 Street Avenger, maybe some of the other fellows can jump in with some info on it.

I seem to remember that the stock static compression ratio was 9.4:1 and since you didn't do anything radical, it should still be about the same. The 0.020" off the decks should cancel out the thicker than stock gasket and leave you with about the same SCR as stock, 9.4:1. Cam may be a little big for the SCR, but isn't totally mismatched. I would have used a 210/212/214 on the intake, but I have an idea that you chose this cam for the lope. I do know this, you will need at least a 750 carb on a hot rod 350. Is your converter a 12" with the fins bent over or is it a 10" unit? That could be part of the problem.

400 horsepower should break you into the 12's, but I don't see you making 400 with a 9.4:1 motor and iron heads.

.

 

Is your converter a 12" with the fins bent over or is it a 10" unit? That could be part of the problem.

.

Just checked, 12 inch converter...
Never have money to do it right the first time...
But always have money to fix it again!
How much power is it robbing me?
I'll yank it out quick for a couple of tenths!

 

Thanks Guys,
She is pretty heavy. 60 ft times were consistent 2.2 and 2.1's.
Its fun to drive on the street, I picked the cam for its torque curve, supposed to be over 400 ft. lbs. for a good spurt.
Tech, now that you mentioned it, I had a Carter on it when I sent the Holley in to repair float bowl under warranty. And it seemed like it was going to rip the tires off when I hammered it. The Holley seems a lot smoother, maybe not as responsive.
I would have kept the AFB on there but it had a flat spot off idle that made it too touchy to drive in traffic.
You guys have given me some ideas, I have taken lots of weight off already and want to keep its factory appearance.
Maybe some dyno time and work on the pump squirter on my Carter.
I feel better now knowing I'm not the only one to spend a couple grand only to go a little slower than expected!

 

The converter is easily costing you that much. Combine it with a 4.11 gear set in the rear axle and you'll pick up 6-7 tenths and possibly more.

You're toting a ton of weight in race terms...3500 lbs is already considered heavy, and you're way over that.

You'll need to get the 60 foot times down into the mid 1.90's or better to get into the 13's.....

Or spray it.

The Avenger line of carbs is notoriously lean in the transition circuit and even lean on the mains out of the box.....I wish people would come and ask more questions about buying one BEFORE they make the mistake.

 

Or spray it.

The Avenger line of carbs is notoriously lean in the transition circuit and even lean on the mains out of the box.....I wish people would come and ask more questions about buying one BEFORE they make the mistake.

Took me awhile, but with an AFR gauge and lots of research got the Holley tuned well. Paid over 4 bills for that thing... Sho does look purdy tho! But seriously, I have the original rear with a broken carrier, will probably put some 3.73's in it and see how it does. I'm gonna have to dig deep to shave a couple hundred pounds, it is a street car in all reality, was just disapointed with the et.
You all have given me a good deal to consider, and really appreciate the input!

 

10 inch converter from a good company like freakshow or one of the other built to order converters is best. 3000 stall with lock up still working for street use. Then run the 4:11 or what ever gear you need to make the rpm peak as it crosses the line then you should be a lot closer to your goal.

Another question is how is the motor tuned did you get the timing curve right fixed all the normal hei issues that often hold back a motor like this. Too much advance and not enough initial timing along with vacuum that comes in slow or not at all and mech that comes in too late and moves too much. are all common issues with hei out of the box setups.

Dizzy is out of the box. 34* Without vacuum hooked up, comes all in around 2800. Watching the light with vacuum advance hooked up looks like it goes over 40* right away. Motor has never pinged yet and pulls well, I'm going to have to research how to dial it in better. I bought the spring kit,just haven't fooled with it yet...
That and a new converter are in order. I need to put her on the dyno before I order from Freakshow.

Thanks Guys You All are Awesome!

 

Read through this....
THE CARBURETOR SHOP / Carter AFB tips

Matter of fact, read through all of these....
https://www.google.com/webhp?source...-instant&ion=1&espv=2&ie=UTF-8#q=Carter+afb+accelerator+pump+squirters+for+sale

Pretty sure the Edelbrock Performer squirters will work on an AFB. Try a larger squirter....
https://www.summitracing.com/parts/edl-1475

.

 

Keep in mind it easier to find 100 ways to lose 1 pound than 1 way to lose 100 pounds.

 

Thanks, I'm thinking about moving the battery under the bed and going with a plastic fuel cell, then swiss cheesing my core support and a few other things. I dont want to make it a death trap, but have been driving it for over 30 years and haven't crashed it yet!

 

Timing!!
It's all in your timing!!
Sounds like you're around 12 initial. You need way more.
Look here.
http://www.crankshaftcoalition.com/wiki/Hot_rodding_the_HEI_distributor


And dropping the tailgate on your land yacht is good for at least 2/10's!

 

AWESOME ARTICLE! Thanks man, I understand now... That thing is very well written. I'm going to bookmark it and go to town this weekend.

 

Braille makes a really good lightweight battery.

You can do that it's a fair amount of work and your better off removing weight in other places.
Look at removing everything you can, shorten bolts, gun drill them, carbon fiber hood and fenders. Aluminum bumpers, sheet metal brackets and mounts, Aluminum engine mounting, LW engine parts, transmission mounts, LW drive shafts, LW rear gears, gun drilled axles, wheels and tires etc...you get the idea I think.

 

Don't forget the weather, hot and humid plus a little altitude not that Marble Falls has much of that but still SAE power has a couple different standards. The old one is rated at 60 degrees F with 29.92 inches of barometric pressure and no humidity. the new spec is 77 degrees at 29.23 inches of mercury and still zip on the humidity. Your real life experience may vary.


By the old standard this engine corrected to that standard should pump about 400 horses and peak with about the same number of torques. The new standard should take about 15 horses away from the old standard's numbers. Again in the real world your actual experience may vary quite a lot.


The carb is small, the rear axle could use more gears, the converter is too tight for the cam, certainly a Suburban is pretty porky; all these things plus the weather are working against going quick.


Maximum acceleration and trap speed happens when you can keep the rear tires just at the edge of breaking loose. You can't get that for a host of reasons including but not limited to engine power.


Bogie

 

If you watch "Street Outlaws" - even though the "Farm Truck" isn't competitive as a full on race car...moving that beast is a yeoman effort, and needs to be appreciated.

Rear gear and 1st gear will help, using your inner fenders to make fiberglass replacements is a fun project and relatively easy. Glass hood, pull the tailgate when you don't need it; drop the spare, lightweight wheels n sticky tires. FreakShow converters is a good place to go for a very high quality, customized converter. An Aluminum driveshaft of the proper thickness tube is a great idea

 

Track Time!

Okay, guys.
Got to make it back to San Antone yesterday and did MUCH BETTER!
After switching to a Holley Blue Pump and shaving about 160 lbs I squeezed out 14.2 @ 94 with a 2.1 60 ft time on my first run.
I have been steadily tweeking things and can tell the difference in seat of the pants as the truck is doing much better all around on the street.
It was lots of fun putting it on brand new mustangs and challengers at the track in a boat I drove 130 miles one way to get there!
Big thanks for all the help, you guys are Awesome!

 

Hello again,
I have moved to North Carolina near Rockingham, and am looking forward to some track time here soon as the weather is starting to cool off at night.
I have, since the last report, destroyed the stock Eaton unit that was holding the 3:42s. I went ahead and got a Tru-Trac carrier and some 3:90s. This thing works amazing! Also have the weight down to 4120 pounds with me in it. Have moved the side tank into the scrapyard, and put a lighter unit between rails behind the axle.
Really want to thank all who have helped me along so far. I will post up times as soon as I make it to The Rock!

 

So you have a motor, a much better equipped rear, a decent transmission and the STOCK converter. You need one, make it a winter project. I was given FTI as a converter option by someone here, and I cannot complain. My trans is 200-4R (similar to your 700) and I was able to grab an FTI with lockup for less than $800. Works AMAZINGLY.

You need a converter.

 

Thanks Nail, I actually have an FTI converter with a 2600 stall. But, I did not know any better at the time, and bought a 12-inch instead of a 10 inch converter. Money is kind of tight right now, so I'm just going to live with what I've got.
Looking for a hood with a stock appearance that will knock some weight off the front, but that's going to cost about as much as a 10 inch converter will! Also, really thinking about a fiberglass front bumper too...

 

Check with these guys for a nice hood that won't break the bank.


Advantage Fiberglass, Chevy and Ford Trucks, Hoods, Bumpers, Scoops, Visors, Fenders
Fiberglass Chevy Truck Hood 1973-1980

 

Thanks Eric.
Always looking for new sources of lower priced parts!

 

Well, made it to the track in Rockingham N.C.
Weather was 82 degrees with 60% humidity 59 degree dew point. I think the elevation is right at 300 feet at the track. Truck currently weighs 4050 with me in it, and brought timing down to sweet spot of 31* all in at 3200 rpm. Finally got into the 13s with 13.9 @ 96 mph. Real world is telling me 290 ponies to the wheel from an Iron Head Vortec Motor with 276 Roller Cam and RPM Air Gap manifold. Truck pulls good on the street, and is fun to drive. But I was hoping for at least 385 at the crank, which should put me a little lower in the 13s. If we look back, and see where I started I have gained 9/10s just moving weight around, and using a little different rear ratio. I really dont want to spray it as I only have stock Hyper U Pistons in it. Someone mentioned earlier to go with a 10 inch converter, that would pick up 2/10s. And I am still thinking of lighter parts for the front, but would like to keep the stock appearance without a cowl induction hood. Any thoughts on spraying this thing? I do have a spare motor... If something went wrong. But am unsure on what to do with timing as it is a fast burn design and timing is already low. Would I need to pull timing back still with the spray?
Or should I just be happy with what I've got.
The old gal puts it down on many of the Mustangs she meets at the track!

 

Some mods at a glance...

 

It strikes me that taking the spare engine and building it as a 383 with some decent aluminum heads is the next step.

Bogie

 

Like this one.

 

You are a Mind Reader Bogie!
Only thing is I just got married and moved my shop 1300 miles from Tx. to N.C. and business is still slow taking off...
Thanks for easing my mind, I know if my Dad could ride in his old truck now, He'd be grinning from ear to ear!

 

I saw earlier in the thread that you were running 13.5:1 AFR at WOT. Are you still running it that lean? If so, fatten it up to around 12.8:1 and it should pick up some power. North of 13:1 is too lean at WOT, IMO.

 

congrats on getting hitched!
Big move man....hustle; start winning some races and people will notice...
You do nice fab work

 

10" 3,000 stall converter
383 using Pro-Filer 195cc aluminum heads. Best bang for the buck in aluminum heads.

 

Techinspector has more knowledge of cylinder head design than I do, but in my search I ended up with Blueprint H8002K 195 cc heads, and then used .026 head gaskets (https://www.summitracing.com/parts/cle-5746) to get the compression up a little to about 9.4 on my old SBC crate 350. I also used a little less cam (213/217 @ .050) because I was looking for a low rpm torque curve that would support hauling heavy loads. Its a very smooth running combination; however, I don't have any way to measure performance other than seat of the pants feel. If you are building a 383 I'm sure you could use more cam.

I've found that about 15-16 degrees base timing, and 20 degrees more mechanical by about 2200 rpm also works well. I have 4.10 gears and stock tires, so rpm comes up relatively quickly.

Bruce

 

I also used a little less cam (213/217 @ .050) because I was looking for a low rpm torque curve that would support hauling heavy loads. Bruce

213 intake in a 9.4 motor is right on the money. And I'm impressed with the flow of the Blueprint heads for the money. Great buy. They only come in 64cc chambers, but otherwise good flow for the money.
https://blueprintengines.com/products/sb-chevy-aluminum-cylinder-head-195cc-assembled-h8002k