Ported 452 or Edelbrock RPM

IQ52 said
So the big question here is what cc did the heads start out as. If they were the 84cc heads to begin with, they would have been milled at least .060" to get to 74cc. This will reduce your piston to valve clearance the same amount, at least .060".

The compression is probably not a problem as the combustion chamber shape will help and the cam is big enough to reduce the cylinder pressure to pump gas levels.

The RPM head should use the same ARP head bolts as the stock iron head.

The pushrods might work as the 452 heads must have been milled to get down to 84cc.

The compression bump and the head flow increase should make a noticeable difference. You can't race flowbenches so..........without a flow sheet from the same flowbench for both different heads it's hard to say for sure.

The rocker arms should switch right over but you may have to space the bolts to the rockers differently to center them back over the valves.

I have flat top pistons with pretty deep valve reliefs. I don't remember exactly, would need to check my notes but they were bit over 6cc volume I think. I have plenty of clearance now, I did some playdoh test and valves barely touched what I put on the piston. I will for sure test this before putting it all together. I am assuming 9.75cc for head gasket. Also there is 7cc between deck height and piston at tdc. So currently I am at almost 106cc chamber with 452s and it puts me at around 95cc with Edelbrocks.

I have plenty of shims and spacers for the rockers so no worries here. Hope pushrods wont stop me like with the cam swap.

I was thinking that perhaps I should sell the RPM heads and go TrickFlow 240 heads... this is why it took me so much time to think about installing them. Car is fun now, I'm just looking for some winter wrenching time well invested here thats all ;-)