Like rk said, swepco oil is the top option. Another lesser option is to purchase an additive product such as rislone or stp that has the letters "zddp" in bold view on the label to add in with your store-bought oil. The last thing you should do is just dump in oil from off the shelf besides what's been mentioned and think doing that alone is good enough. Read up on topics like "zddp" and "premature lifter/cam shaft wear in flat tappet engines" and you'll understand why. Also, just say no to fram oil filters. They're the worst, bar none.