I've been running 91 oct E15 CA pump gas. Heads are RHS/Indy X prepped by IMM. I'm assuming by 'Q' you mean quench? I'd have to double check, but i believe it's around 0.037"? If I recall, pistons were 0.015" out of the hole and I'm using 521SD gaskets. I'm picking up another timing light tomorrow btw.