> if you bump the comp to say 10:1 the output would jump to around 160-170

You expect a 37% increase by going from 8.5 to 10 compression?

What examples do you base this expectation on? The calculator says you'll get a 5% power increase.

Higher compression will not make the engine breathe better, and low compression likewise doesn't prevent the engine from breathing -- it doesn't choke your carbs.

I can't remember the exact equation that we did in chemistry, but basically it meant that under controlled conditions, a reaction taking place under a higher pressure (higher compression ratio) would yeld higher energy (power) at a linear rate......
So everything else being equal (i.e. NO other changes to carbs, cams, etc etc etc) if you increase compression ratio, you WILL increase power

Obviously due to phsical limitations of the engine, other constraints come into the equation including pre-ignition/detonation, so we all can't go jamming in 14:1 alcohol rated compression to make 300hp from an A15

AFRacer a closed chamber head would make much better hp and torque for those dished suckers it is a much more efficient use of the kidney chamber as it was designed to be that way to take full advantage of its design principles for inlet and exhaust on the same side. In theory open chamber heads are better for the hemi type arrangement with convex pistons and crossflow. You could be gaining more hp than the 5% on stats because an open kidney chamber head supposedly has more of a disadvantage with the same compression than a hemi opened head as it upsets the swirl pattern it was designed for but used by nissan for low grade fuel in certain countries. As for Optimaxproblems... Dont use it unless you warm up your car to full operating temp, otherwise a black residue coating will cover your plugs and ruin your points or timing. Synergy is best and havent heard anything bad yet about it and most top racers swear by it. Stay away from lead free super its got something in it that is like acid to your oldschool engine which makes sense since big brother wants you to buy new cars.
Hope that helps.