I know a fellow running a 422 stroker with ported Eddy. aluminum heads running 11 to 1 compression and no problem at all running 93 octane. But he is also running a much larger cam which will bleed of some cylinder pressure. That cam you've picked is really small for a 422 cubic inch engine. Should idle nearly like a stock engine. If your set on that cam I wouldn't go any higher than 10.5 to 1 like Terry said.