I think you hit it on the head TMM, and I have been through that before and figured it out.... I just have forgotten. The reaction at the oil pump gear pushes the cam one way or the other. (I am also pretty sure the lobes are not flat front-to-back.)
" A flat-tappet cam’s lobes are slightly tapered to promote lifter rotation. Roller cams feature a nontapered lobe surface. Because the lifter bearings roll across the cam lobes, this virtually elimin........................"
