Timing Light Accuracy

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.
Those are Iron heads, right? Glad you figured out how to make that work. I bet that's a sharp combo.