[Keithc8]

It sounds like to me that all of the heads you are talking about is to much head for this engine. It will be a real dog down low. Unless you plan on running 12 to 1 compression and do not care what the engine does below 4000 rpms you can go with any of these heads. There are to many wedge heads that will do the job and I would not do the canted valve 351C heads because it is a pane in the ass to do.
You could do a nice CNC ported AFR 185 or our KC Signature 195 head and have a much better engine. You will have to turn the engine up to get a 302 to make 500HP. It takes a complete package and most people over carb and cylinder head their enignes.
We make 750HP with original 428CJ cast iron heads ported on a 11 to 1 440C.I FE 428CJ engine with a Dove single plane intake and 735 carburetor. The heads only flow about 340 on the intake and 260 on the exhaust. Let us know if we can help.

Thanks, Keith