360 build
Cool! I'll assume the pistons are stock replacement stuff. They will be a fair ways down the bore,.060 at least.
Go here and download this program.It's free....
http://www.compcams.com/CAMQUEST/
This program will help you determine what final compression ratio and cam will work best together. These programs are fairly accurate so it should give you a realistic idea what to expect for power too
I watched the episode of hoserpower tv where they build a stock compression 360,stuck a summit cam and a 650 on it and made 317 h.p.If those darwin award retards can make that you can easily make 400 h.p