9.6:1 isn't too much at all. You will be boost limited on pump gas, but on race gas you'll be totally find with a decent intercooler.

Timing will just depend on what fuel you have in it, and how much boost you run.

I ran as much as 26 degree's on 20psi with non-intercooled E85, with iron heads at 9.2:1.

You won't want to lock it at 12 for sure, it will drive awful off boost. Need to have something that pulls timing as boost increases.