max compression on pump gas\steel cylinder head\241 @ 50 cam

If you have 148psi with that cam there might not be much gain from advancing the cam. I use the dynamic ratio to plan octane. Open chamber iron you can't have any quench. That does negatively affect how much you can do, but I use 8.25:1 dynamic and a cylinder pressure of 185 as my limit for pump fuel. We had the 87,89,91,and 93 here all with 10% ethanol and using those figures I can run as low as 89 octane with any timing I want.