[davepl]

Originally Posted by David Maddux

From what I understand of the loss of zinc in our oils, is that it effects the older flat tappet motors, as in our old Allis Chalmers tractors. It is eating up the cam shafts. Where you have a rotating lifter you have no problem.

I think you mean rolling lifter - all lifters rotate (until they fail and stop!) in their bores, that's why the lobe is off-center when you look in the lifter bore.