Rick,
If you are running a stock engine with a flat tappet cam look for an oil that includes zddp, zddp (Zinc Dialkyl Dithio Phosphate) is an additive that enhances lubrication under extreme pressure between the cam and the flat tappet lifter.
Because of emission standards and incompatibility with catalytic converters many of the oil manufactures stoped using zddp in their oils. Shell Rotella heavy duty diesel oil did include ZDDP but I believe they have reduced the levels. I've heard that
Amsoil 20W-50 Series 2000 is the only oil that includes additives equal to the ZDDP wear protection.
You can find Extreme Pressure Oil Additives, Eastwood offers
ZDDPlus which is an additive for any oil that you decide to use. You may be able to find these additives at some of the auto parts stores.
If you have roller lifters you do not need zddp,
Good luck,