have brand new 540 dart short blocks, used my 502 heads off merc 500hp, machine shop refreshed all heads, up graded springs, comp cam and hyro lifters, crane roller rockers. engines run sweet untill 2800rpm then all hell brakes loose, the lifters sound like they are going to jump out of both engines, back it down they quiet down, 60 lbs steady oil pressure both engines. have triple checked everything. will check it all over again if any one has any ideas

is the geomitry right,are the springs correct for the cam.are the lifters adjusted properly,it sounds like something is out of wack.

everything from cam, lifters, springs was all supposed to be matched from the same place that built the engines, the only thing we used different was the 502 heads

.100 pushrod difference?