CR and pump gas question

I would always run the closed chamber Edelbrocks over the open unless you NEED the open chamber heads (like with stock 340 pistons).

Aluminum heads dissipate heat much better than iron, that is why you can run more compression with aluminum heads and not run into detonation. Typically, you can get away with premium pump gas and 10.7:1 (even higher compression depending on cam selection).

Also to note, stroker motors eat up cam duration...meaning, you can run a larger cam and it will "act" like a smaller cam...if that makes sense (max power will be at a lower RPM than advertised).
It seems more like the combustion chamber in the aluminum heads has more to do with less detonation than the iron heads. Tests with the same combustion chamber shape in iron and aluminum have not confirmed the ability to run more compression. Nor does it show that the iron heads will make more horsepower.