Well, the multi-morphing rebuild for our 72 Coupe formerly L48 small block has taken another turn. We decided not to stroke it (we think we can get over 400 ft lbs torque and close to 400 hp without stroking - probably more than the tires can handle anyway). I finally settled on Air Flow Research 180cc aluminum heads with the combustion chambers milled to 64cc, block bored .040 over, a Comp 268H cam, forged pistons and I-beam rods, dual plane intake, and the usual other goodies like clevite bearings and felpro gaskets and such. Dave at Air Flow has been very helpful in getting me this far, and when we're done we'll end up with about 10:1 compression.

Dave says I really should put headers on this beast (he says if we run it hard it will burn out the center of the rams horn manifolds), but I don't want to constantly be messing with the usual header leak issues. I'm looking for a balance between beast and bulletproof on the engine. Two different experts have told me to go with 3/8" flanges on the headers, but neither knows what exact headers will fit inside the C3 engine bay/route appropriately under the car. I called Hedman, and they don't currently have a 3/8" flange header for the C3, although they say they're working on it.

So, forum experts, I need some help:

1. What kind of headers will work in the C3 with such a setup (long tube, shorty, block hugger, etc.)? This is going to be a street car, so I'm more interested in bottom end torque than top end horses, which would slant things toward the long-tube variety. I'll be mounting a turbo 400 tranny with 3.55 rear end, if that matters (yes, I know, my gas mileage is going to sucque - I didn't buy a Vette for gas economy).

2. What brand of headers, and which particular model(s) will fit in the the 72, and what kind of modifications will be needed? The air pump and its associated parts are coming out (Virginia exempts cars > 25 years old from emissions inspection), so that may make a little more space available. The Air Conditioner is going back in, though.

3. Are there any other things I should do associated with the header install (mini starter, coatings, etc.)?

TIA :cheers:

 

I installed Doug Thorley Headers on our 383 ’69. Custom fit for the Vette. No problums with AC, or PS. 3/8” flange. Corona Ca. 909-735-7280.

Bought bare and sent off to Jet Hot for coating.

Find Stage 8 locking header bolts.

George

 

Stage 8 locking bolts and a good set of header gaskets (copper, alum, etc ) that are guaranteeed not to blow will solve your header issues.....Summit's catalog has all that stuff.....ENJOY :jester

 

The Dynomax Coated headers. The fit is great & someone posted that they did some slight grinding on the 68-76 a/c bracket. Any premium gasket should be fine. Stage 8 locking bolts rec. if you are concerned.

:cool:

 

Just finished installing Dynomax Coated, Percys Dead Soft Alum gaskets and Stage 8 Bolts, along with AC bracket ($12.00 +/-) all purchased from Summit. WEnt real smooth and pretty good fit (no leaks). Also got Summit Dead soft Alum Collecter gaskets.

 

Same here last weekend without the stage 8 bolts and NO LEAKS..... :cheers:


[Modified by Alwyn678, 8:58 AM 1/25/2002]


[Modified by Alwyn678, 11:39 AM 1/25/2002]

 

Thanks for the info so far. Looks like Dynomax is popular. Does anybody have a part no. for these?

 

I installed Hooker Competition Header in my 70' this weekend and they fit great. You would need an A/C and Alternator bracket along with reducers to connect them to your stock exhaust, but they look great. I also had mine ceramic coated before I installed them to keep the under hood temp down.