6 pack piston zero decked and a closed chamber head with about .035-.040 piston to head clearance and you could run close to 10-1 with a smallish cam (closer to 11-1 with an aluminum head). Like everyone else said run as much as you can get away with and a tight quench. You will not need near as much advance setting up the engine this way. Personally I would run another full point of compression and run premium for more power and MPG, the trade off in cost per mile (almost none) is worth it. I would run a cam around 210@.050 and 110 LSA and as much lift as you can get in that amount of duration. When pushing the boundaries of cylinder pressure you will want an intake with good fuel distribution and no heat crossover like an eddy RPM.