Edelbrock Rpm heads on 360

with that cam the 318 headers will work fine,new would only help at the top end where that cam is going to run out of breath anyway and might hurt low end
try them b4 you change
that cam should work fine with true 9:1 and plenty of lift for that duration compared to a lot of "white box" cams that only give you .420 or .440
I have run a similar cam in a 9:1 360 with ported stock heads- but with KB pistons .020 over
did you ever report how far down the pistons are or what hyper piston
? why not the KBs ?
if you do come up with the numbers NM9 will run the numbers for you
ask lunati where you intake closes at .006 I'm guessing around 56 ABDC they give you .050 timing for degreeing the cam but not the seat timing for figuring dynamic compression