I hope I can get some help on this one. I have tucked away my '81 Z for the winter and my project now is the Camaro's little cousin; my '75 Vega GT. I have a '78 350 L82, M21 and 3.73 10 bolt posi driveline in it. (fun car). The heads are stock -76cc chambers (forged flat tops) 9:1 compression. I'm running a 280H magnum Comp cam(love the idle). I want to up the compression with Aluminum heads and try to get some more power.What would the compression ratio be with 64cc or 70cc chamber AFR 0916 180cc Aluminum heads? I have 2 intake/carb setups. Wiend dual plane-Holley 600 dbl pumper(on the car now) or Wiend Team G single plane-Holley 750 dbl pumper. What should I do...so confussed. Any help would be so appreciated.

 

My mistake those AFR heads come in 65cc or 75cc chamber. Would 65cc heads bring the compression up ?

 

I think that would bring you up to a tad over 10 to 1. Any chance you could post some pics or maybe dedicate a progress thread to the Vega. I'm sure many here would be interested in seeing it.

 

Thanks Pablo63, any thoughts on intake/carb with these 65cc AFR heads? I will try and get some pic's on soon.

 

Wow, thats some serious info 77nomad. Thanks, I've got some work to do.

 

To truly know your compression ratio you need to know. How far down in the hole are the pistons? What is the volume of the head gaskets you want to run? The chamber volume. Thats your static compression. Your dynamic takes the cam timing into account. Your exhaust valve being open for any given time as the piston comes up will bleed off compression. This is how I got my 383 set up with 59cc heads. I keep the valve open to bring it down, that way it will run on pump gas.

The motor is going in the Vega? I would run the 750 with the duel plane on the street, for a street MORE than strip car the Team G is hard to beat. Thats a big cam for a street motor though.

 

I've run this motor for years in the Vega. It seems to like higher rpm range. Above 2500 to 6000 (4 speed) I have run it on the 1/4 mile a few times. 14"street tires, low 14.3's at 98 mph. I now have 235/60/15 Mickey Thompson ET Streets,would like to do the heads and try again. Don't forget this purely a street car. I go to Mission Raceway once every few years.

 

Anyone else have any thoughts on what heads/intake/carb I should use on my Vega to get the most out of this street car ? 350-4speed-3.73

 

If is a street car then the duel plane for sure. 14.3's? That seems pretty slow for a Vega? I was running consistent 10.80's w/ a 355 in my Nova. The Vega couldn't be much heavier.

 

I'd guess the Vega is much lighter, and probably suffers from traction issues. A good pair of race tires will help those times a lot.
With your setup I'd probably go with a chamber size of 59-65cc and runners of 190-195. It's going to depend on whether you run a thick gasket, or a thin, as to compression, but I'd go with a Felpro Blue thin gasket.