Using : Bore 4.18, Chambers 92cc, Valve releifs 5cc(SRP's), Area above top ring 1cc, Compressed gasket .041, Deck clearance .005, Static compression is 9.73. Using an intake closing point(XR288R) of 44 degrees ABDC, DCR is 8.84. Refuse to make any call on Octane required, I defer to the Dude. Heck, If he told me it would run on it, I would Pee in my gas tank-
He's Da Man- JimT