
Originally Posted by
glennsexton
This could prove to be an interesting experiment. The 624 head is a low compression (9.0:1), 76-cc open chamber head. In all likelihood the ones off an ’82 Corvette were 2.02/1.6 valves with 165cc runner volume. The intake runner volume influences how the combustion chamber is filled during the intake stroke. Smaller runner volume(s) increase the velocity of the air going into the combustion chamber and as such, they build more torque at low rpm (when using stock or near stock intake/carburetion). As such, small runners are best for street cars. They typically accelerate better off idle and perform well below 6,000 rpm. However, at higher RPMs, the small runners restrict the airflow, limiting the output. As mentioned above, the 624 heads can be used successfully but one needs to pay attention to cracks.
Your Victor intake and 850 CFM carb need a larger intake runner volume (180 - 210cc) to be effective and typically do not perform well below 2,500 RPM.
Larger runners will provide better fuel distribution at high rpm. This increases horsepower; however, they don’t start making that horsepower until higher in the rpm range. This results in poor performance on the street.
The Floteks have smaller combustion chambers (62cc) and larger runners (180cc) so they will provide some compensation for the over carburation. It could prove to be quite acceptable and it sounds like you’re familiar with the combination so you know that if you let the clutch out at 1,200 RPM you will bog like an elephant in quicksand. Once you’re rolling and at about 3,000 it should jump like a scalded rabbit.
So back to your original question (and I definitely hear you on the money side of things!!), I’d still shy away from the 624 heads, go with the Flotecs (with new bolts, pushrods and the recommended gaskets) and drive it like you stole it!
Have fun,
Glenn
A belated Happy 78th Birthday Roger Spears
Belated Happy Birthday