I have the Hughes springs and retainers on the magnum heads with .510 lift the seals just clear so I wanted to stay a little less then that, that's why I was thinking around .500 max . My current 318 runs a factory 340 automatic cam which is 210 & 220 @.050 runs good but I doubt the compression is even 8:1 and lift is only .421 .444 I believe. I had thought of running that in this motor with the 1.6 rockers but I think there are better choices then 114 center line, I think 110 would probably work better. Something like the comp 20-417-3 perhaps, although I am not sure a dual pattern cam will make much difference on a street car but they are widely used when running full exhaust.