Why this fixation on 10.5:1 ? Last thing you want is a pinging mess of an engine. You would need a fairly large cam with 10.5:1, You can run a fairly decent size cam with 9-9.5:1 CR, just don't run more cr for the hell of it. 10.5:1 over 9:1 is only about a 5% power gain so about 15-20 HP.