How big is the cam. That was a problem with the BBC's when you got over .500 lift with the stock rockers. They offered a long slot rocker to correct that, but it was still stamped. Pull a couple of other rockers off and look at the slot where it fits over the stud and see if any are showing signs of rubbing the rocker stud, should be shiny if it is. Not sure how much the stock rocker can take as far as lift or spring pressure(hyd. or solid lift), there different even if they are the same lift.
