I have been using Brad Penn Penngrade 10/30 in my FE and SB Fords race engines, which are flat tappet solid lifter cams, and now in my solid flat tappet 428 in my 59. Never had any cam/lifter issues, and everything always looks great. My new SBF has Morel hyd. roller lifters, but I will continue using the Brad Penn in this engine as well. My machinist buddy has been using the Brad Penn in his solid roller, high RPM Super Stock engines, and he says that he has never had the pushrod ends look so good in his 9000 +RPM engines, as they did once he started using the Brad Penn.