Edelbrocks are a great entry level aluminum head. Whether or not they flow better than the GT40Ps is debatable. especially at low lift. Edelbrock, as they make heads for basically everything from AMC to Pontiac, has standardized as much as they can across their product lines. Pretty much all the heads use 2.02/1.60 Chevy valves. I also want to say that you are limited to like 0.550" max valve lift with the stock springs. I believe the GT40Ps have a 195 cfm intake port, which is probably what the Edelbrocks have. You don't want a bigger port on a smaller engine,as it'll get lazy down low.
AFRs are a better head than either the Edelbrocks or GT40Ps. They should be considering what they cost. How much better are they? Most of the reading I've done says an AFR 165 is probably worth 50HP over the GT40Ps, BUT that's assuming everything is 100% dialed in to those heads. With the existing cam I would expect more like 25HP.
BUT, I'm also thinking this is a proposed solution to your belief the engine is down on power. I'd make sure the engine is sorted before trying to fix it by swapping expensive parts. Check compression, verify TDC on the balancer is really TDC, make sure the timing is set right and the curve is right. Make sure fueling is right.
Last edited by TKOPerformance (9/16/2024 2:46 PM)