My motor is similar to yours and my cam lobes are a little different, 260 @.050 intake with .430 lobe lift and 266 @.050 exhaust with .409 lobe lift, H.S. 1.65 actaul ratio at the retainers ground on 108, installed at 106 to 107 depending on which valves are checked I check the both the # 1 cylinder and the # 6 cylinders valves at the retainers for LSA and actual lft with both checking springs and the ones that will be used when the motor is used and the lobe seperation on both the intake and exhaust lobes do that and you may find some information you didn't know or suspect