Open or closed chamber head? If they're closed, that .019 gasket is a non starter anyway with zero deck.

I'm not sure how much credence there is to the so called rule of thumb that says aluminum will support a point more compression than iron will before detonation, but if it will and you have closed chamber heads, guessing your gasket bore at 4.4 and 4cc valve reliefs, my calculator comes up with 10.8:1 with a .039 gasket. .039 gives you a safe piston to head and excellent quench distance which is critical to make a pump gas combo work.

With an MP590 it should be good with brand name 93. 100 degrees of overlap should help bleed a bunch of cylinder pressure at low RPM.

I'm not sure if I'm confusing BSB67's build with someone else's but I thought he ran the MP528 which is supposed to have 60 deg of overlap, so if he doesn't rattle at 10.8, you should be golden.

You might have to play with the timing curve a bit depending on what converter and rear gear your are trying to haul 4000 lbs out of the hole with.

Kevin