I was led to believe that roller lifters in a FE were a short life item and trying to stretch the life of the lifters was a gamble on them not comming appart before you change them. I was told that the FE doesn't have enough
oil at street revs to lube the rollers. Maybe they have made some changes since I last asked Comp Cams. I wasn't happy when two shell lifters and lobes went flat.