Ok here's my current engine setup. 1977 L48 with Holley 4160 VS and Performer RPM air-gap intake. I'm looking into heads whenever I can save up some $$$, so while I wait I thought I'd get some oppinions.... What I really want is tire spinning, throw you to the back of your seat torque! So when I make my head decision, what should I look for as far as intake runners, exhaust runners, intake ports, exhaust ports, exc? The cam is going to stay stock for now and even when I do change it I want to go with something less aggressive. While I'm on the subject, I really want to go to a roller cam setup when I do change cams so will it be feasable to just buy bare heads and reuse my old hardware TEMPORARILY until I change cams? I know very little on this subject so feel free to impart your knowledge upon me!

 

I would do the cam first, then the heads.

To help answer your questions though, smaller runner volumes help keep the air velocity up and this is good. Large runner heads may be able to flow more and feed a larger engine, but your air velocity will suffer on your engine. Smaller runners help with throttle response and low end torque. There's no reason to get exotic with the ports so stay with a cylinder head that will work with the intake you have. Honestly, I like Edelbrock's performer RPM heads. I've used them a few times and they worked very well.

We built a 76 4 speed vette a couple years back. The short block was done by a machine shop the customer chose and we assembled the rest. The build was just a standard rebuild nothing high performance. We used out of the box Edelbrock heads, Edelbrock intake and carb. The machine shop chose a small Elgin cam. The car ran fantastic. Pinned you in the seat when you nailed it and pulled hard to red line. Sounded fantastic through the headers and magnaflows. There were no power goals of any sort with this car. The owner simply wanted to cruise and run well. The car ended up making 300 hp and 335 torque to the wheels though.

Couple other things to consider. What's your rear gear ratio? Changing it could allow you to better use the power you have now and will have in the future. Torque converters don't have to get ridiculous as far as drivability to have a very positive affect on the performance. I'd still invest on a cam shaft first, then the heads.

 

Edelbrock Rpm intake fits under your hood w/ a Holley carb? I'm looking to get a Performer RPM but was told it wouldn't fit under the hood of my '74. As far as heads, go with the Edelbrock heads. Their combination for Performer RPM Intake, cam, carb, and heads is advertised at 410 hp if I remember correctly.

 

Yes, the RPM air gap fits, but just barely! I'm using about a 1.5" air cleaner and for that reason I'm upgrading to an L88 hood to gain some clearance. About every oppinion I've gotten said go Edelbrock RPM. So for you guys that have gone with these heads I have a couple questions.... Do these come complete with a 3 angle valve job? If not, how much to get this done at a machine shop? I'd like to get 64cc combustion chambers; if I do what kind of compression will that give me on a stock L48 bottom end? Thanks