looks like the camshaft was walking (taking a very hard walk) in the block,...why? what was the end play in the crank? lifters were rotating, i can't see any lobes flat. foot of the tappets could have been damaged from all the metal debris. what caused the cam to thrust to the rear of the block? this needs a better postmodern than flat tappet syndrome. i messed with that lobe profile some years back and i came away thinking it was very gentle. what was the over the nose spring pressure?,....not that i think spring pressure did this but using a small tappet with a 1.72 rocker those numbers need to be checked. i think maybe there was a major engine assembly issue. not enough things checked or cleaned.