we lost a cam on the dyno last summer, in 350 2bbl dirt mod. it was a p55 core with hi polish hyd lifters, and brad penn break in oil. we were running z28 springs for break in,only took about 20 minutes :cry: checked the system one filter and found iron in there. the lifters were worn more than the cam. only 3 and not real bad junk just, the same filter trapped all the junk,swapped out the cam&lifters ran great.the last one that went flat had joe gibbs in it,that was in 2007. we like the crower lifters with flats on the sides hyd, or edm holes solid. since then we have ben checking lobe taper on every cam. some cams dont have much=low or no lifter rotation. it olny takes one bad lobe, and you cant tell by looking i ran 3.56 stroke 400s 404 sounds like fun stickboy331