lifters
If you have a non roller block, why not pick up a roller 318 or 360 block from a dippy or a van - lots cheaper to go that route if you are determined to use a roller cam. That is - if your present motor needs to be rebuilt. Take a look at the costs of the retrofit tappets, then look into the cost of the already fitted later model lifter set up. The lifter set up is the key. Good luck.