[A2000RICH]

Amen to the idea that a lot of the wear issues are related to the quality of the cam and lifter. If you look at an OEM cam and lifter (take GM for example) the cam lobe is highly phosphated at manufacture, and the lifter has a special alloy foot. After break-in, the path of the lifter foot on the cam's surface polishes a smooth shiny path on the cam. To quote an excellent paper on the subject, SAE 2004-01-2986:
"One outcome of all this (research into cam wear) activity was the standardization of hardenable alloy cast iron camshafts and lifters with a phosphate coating on the camshaft."
In this same paper the authors explain that the wear characteristics of the cam-lifter interface are largely due to the carbide properties inherent in the cam and lifter alloys. The carbides are formed during the hardening process, and the authors believe that the phosphate coating works in conjunction with the carbides in the cam and lifter to wear away the softer cam metal, leaving a carbide wear surface. This surface, if properly formed during break-in and maintained by oil with adequate ZDDP, is capable of long wear. This cam specification adoped by the OEMs years ago may not be what some aftermarket cam and lifter suppliers are using. In particular, I have not seen the hardened special alloy foot on aftermarket lifters.