Kick them in the rear, I've asked for input from three "experts" about heads and compression etc, Canfield or AFR. I do want a little extra compression, and the head choice will affect piston choice and/or compression. They can be had with 72cc or 65cc in those, and the pistons jump from near flat, to 14cc dished. Somewhere in there is a compression I'd like. I need a balancer worked out before I actually make a commitment to a builder. The pulley is more of a deal for me because I need one larger, near 7" if possible. Hopefully the odd 4.6 pulleys that they have will be the answer, those are more common than the 94/95 Mustang type.