Using a roller cam in a pre 85 small block

Comp has a set of solid roller sthat are drop in in some blocks, but the only way to make sure is to buy them, and fit them during mock up. I wont use rollers unless the lifter bores get bushed. Tubing is another option, just make sure you do both galleys. There are retrofit hydraulic rollers, I thought they were drop in with a new pushrod, but I havent used them before.