It sounds like you already have the right head on the car for what your doing. If they are the same head as an RPM your all set. An EZ head would be nice, but I ran a low deck 451 with your cam(590) and Eddy RPM heads, went 9.80's at 3050#'s. Your carrying alot more weight but should still run good.

I also think those CNC ported Stealths look like a great deal, assembled by MCH.