Thanks! If I retard the timing, would I be able to up the compression? I'm thinking about building a 393 stroker, but i am undecided on compression ratio. It will be an everyday driver so its gotta run off pump gas, but i'd hate to miss out on more power!
My Dad's old 69 Mach 1 ran 12:1 compression and he had the heads milled another .020 over, so he was closer to 13:1. He had almost a .600 lift cam with a 235/238 duration @ 0.050" lift, and it ran perfectly fine on 93 octane with 4 degrees of ignition timing. If he advanced the timing up to 12 or 14* he'd have to run 100 octane. Even with the 93, the car ran low 11's.
A safe compression to run on the street is 10.5:1. You can still run plenty of cam, and a pretty aggressive base timing setting.