My 518 with Eddy RPM heads loves the H.S. 1.6 rocker(actual 1.64 ratio) with a .420 lobe. The actual net lift at the retainers is around .710 to .730, love the differences bewtween rockers ratios on the same set As far as to much lift on a BB Mopar type head I don't think that you can get therte from here More lift is better if you want more power as long as you have a stable lobe and valve train that will handle it