I got 20 sum passes out of my 1st BBC before roller lifter broke, cracked/dented the block in the cam tunnel,ruined the cam, beat up 2 of the rods around the cap where it smashed into lifter parts. So much crap went through it the crank had to be turned.
to make it worse the block was a december 69 cast 512 block(1970 ls-5)