The online CR (static) calculator I like best is the one on the Diamond Pistons web site (diamondracing.net).

I don't know how big the cam is you're talking about using, but if you have 11.5 CR and anything smaller than about 275 @ .050", it'll probably ping on pump gas. I'm expecting to be at (or over?) the limit for 93 octane w/ around 11.0 and something in the 265-268 @ .050" range.