383 Build

I've got a 383 with the 906 heads going into my '72 Duster and I'm trying to get as much compression as I can out of it without using domed pistons. First question I have is this: I've heard you can 'zero' the deck relative to the pistons to up compression. can someone clarify? Also, does anyone know how much can be milled off the stock heads to reduce the combustion chamber volume? My third issue is this: how much cam can I get away with and avoid having valve/piston clearance issues? or is there an easy way to calculate the interference?

for reference my plan is to use the flat top speed power forged pistons bored 0.060" over, forged rods (not sure which kind yet), a Mopar Performance single plane M1 4bbl intake manifold, either the Schumacher or TTI A-Body headers, and would like to shoot for 450 crank hp.