[Alan Roehrich]

Adger is correct, Comp is not taking their additive off the market. GM EOS is a hit or miss deal, they have some, or they don't, you never know if or when, get it when you can, and buy a case. I'm betting the disaster that they are in now will not make that better.

Be aware that you can only get so much ZDDP to blend into motor oil, and more is not better. Excess ZDDP can cause problems, it gets into places it should not, and leaves deposits. If you have a real race motor oil that has ZDDP in it, adding the other stuff usually will not make it better.

Some of the synthetic oils use ZDDP, some use other additives. Some work, some do not.

The big block Chevy is notorious for eating cams. You'll often get a block that will just eat flat tappet cams, period. That is the best reason I can give you for boring the lifter bores out with a BHJ fixture and bushing the lifter bores. You'll note blocks that eat cams often score the front behind the timing gear. That is also often caused by an out of position lifter bore. Or three. Or four.

NEVER buy a cheap lifter. You cannot possibly save enough money to pay for the risk. One flat cam lobe will cost you a complete rebuild. Now, was saving $50 really worth all of that? Cheap cams are the same way. What you save won't buy a gasket set and a case of oil and a filter.

Bill is also correct, the nitrided cam is the way to go. When combined with a true high quality lifter, and the correct break in procedure, the results are excellent. What you're after here is to have enough crown on the lifter face, and enough taper on the lobe to make the lifter spin. But you also need the lifter and cam to be hard enough to slide on each other. Finally, the finish on both pieces has to leave them slick enough not to stick to each other.