[Blackbirdws6]

That's a loaded question but speaking for what you are doing, shoot for a 9.0 to 9.5 SCR. You can get there with a -20 to -31cc dished piston. Mines right around a 9.0 SCR with the -31cc piston and the same combustion chamber size. If you don't plan on much more boost, JE makes a nice off-the-shelf -22cc extreme duty piston for boosted applications.