MattG

Hello everyone, I do not currently have a C3, but definitely hope to sometime in the near future.

I have a very good friend with a 1976 that is getting a new engine built this winter for it at Agostino Racing in Toronto, Ontario. He is sticking with stock block and rods (with ARP bolts) but is going with a new Stroker Crank, forged pistons, custom ported/valved vortec heads, and a very decent sized camshaft. We figure he should make around 420-430hp at the crank.

My questions are:

What exhaust would you guys recommend? He wants something that will sound nice and beefy, but not have TONS of resonance. He still definitely wants to hear the lump of his camshaft. I am not familiar with exhausts for C3s at all. How are they sold? just mufflers, or complete systems?

What Long Tube headers would you guys recommend? What diameter would be best for his application, 1 3/4"?? Are long tubes possible on his car? I know things look like a rather tight fit under the car.

What Torque Converter would you guys recommend for such an application? He is going to be mainly using this car for Street use with the occasional trip to the 1/4 mile with drag radials. He wants it to be very streetable.

What carburator would you recommend for this engine? How many CFM? 650-750??

Any advice or experiences you guys could share with me would be GREATLY appreciated. I have a personal interested in this car getting done right because he is a very close friend of mine, and becaue I want to drive it a lot! :D :D

Thanks in advance.




[Modified by MattG, 4:03 PM 12/2/2001]

1979toy

Can't help with the exhaust or mufflers. Try the Dynomax ceramic coated headers in 1 5/8ths for the best fit. You might want to look at Hooker Super Comps if you want 1 3/4 inch. I would use the 1 5/8ths.
Your cam selection will determine what torque convertor that you need. Try to stay in the 2000 to 2400 stall RPM range for street drivability. Lower is better for the street but may not let your motor get in to the power band soon enough.
750 CFM carbs are a real good selection for a 383 small block. Vacuum secondarys will help on the street but mechanical secondarys will let the engine rev faster when it gets adjusted right. Only you know if you want to live with the extended tuning time required to get mechanical secondarys to work properly.
If you're going to ask the questions you've got to post the results. We'll look for them in the performance reg. in the spring. :D
Enjoy.

70L46

Matt,

How loud does he want it to be? There are a lot of choices for mufflers. I have the Dyno Max Super Turbos on my 70, and they are a nice compromise between an agressive exhaust note and not too much resonance. They are too quiet for my tastes though. Of course Flowmasters are popular, and I have heard some good things about the Raven muffflers. I'm guessing he would probably be most happy with a 2 chamber Flowmaster (I assume he is (or has) dumping the cat and running true duals). His best bet is to get the headers and mufflers he wants, then have a good muffler shop fab the pipes to coonnect them.

As for the carb, if his budget allows, he should check out the Demon line, they are awfully nice (and look really bitchin' too :) ). If the budget is tight, a rebuilt and properly set up Quadrajet can support the kind of HP he's looking at.

Is he gonna have all this stuff done in time for the Cruise In? :D


[Modified by 70L46, 5:46 PM 12/2/2001]

Ganey

Matt

Dynomax coated headers which flow great & Turbo mufflers. Holley 750. Stock converter can stall around 2000 w/ 383.

tnt76vette

I think everybody is assuming that you have 4-bolt mains instead of 2-bolt mains in this application. 2-bolt mains might be reachin a bit in this application with over 400 HP. My $.02 ( .03 Canadian) :jester :seeya :flag


[Modified by tnt76vette, 9:12 PM 12/2/2001]

MattG

Thanks for the information guys...

I think I am going to get him to go with the Flowmasters. I know he wants it to sound pretty beefy and mean.

At least I know what headers are offered now for it and we can go from there.

As for the carb, I think he has his heart set on a mean lookin Demon 750...

Do you really think a 2-bolt main wont be strong enough for this motor? He has no plans of every spraying it, and I highly doubt he will be driving it to hard. I was told a 2-bolt main is fine up to 500hp and this engine should be about 70 or 80 under that.

I will definitely keep everyone up to date on the progress of this engine. I can't wait to go for a ride in this thing when its done. I have a real weak spot for older vettes with a big lumpy carbed engine :)


Any more suggestions?

Thanks,

vettesite

I have 2.5" dual pipes, no cats, H pipe (balance pipe) with Flowmaster 40 series Delta Flow mufflers on my 1980 modifed Vette and I like it. It has that classic metallic Flowmaster sound, it really brings out the sound of the cam, and flows well but there is a fair amount of resonance inside between 1600-1900 rpm. Others have put the 50 series on an reported less resonance inside with a pretty aggressive sound outside. You can buy them from Summit Racing. Check out my signature for the part numbers.

I have an Edelbrock Quadrajet #1904 on mine and it's perfect.