[dataway]

I still think a source of many lifter wear problems are lobe taper, and lifter crown mismatch from different manufacturers. Probably no big deal if a cam lobe taper is off 0.0005 ... but if the lobe taper is off 0.0005 one way and the lifter crown is off 0.0005 the other way ... could lead to problems with lifter rotation and consequently lifter wear.

I had good luck with Melling cam, and Melling lifters. Both mic'ing very well before installation. Best lifter by far I've ever measured is GM NOS lifters ... zero error that I had the ability to measure. Good chance NOS GM lifters were also made by Melling.

Materials are important, but so is the quality of the machining. I tend to trust a manufacturer that is both machining the lifters and the cams in house. And I think high volume manufacturers are likely to have the most modern machine tools.

Some of the highly touted lifters I've measured have surprisingly loose tolerances on their crown machining. If you have a decent lathe, surface plate, and the measuring tools, sometime chuck up a lifter and check the face for perpendicularity to the sides and crown taper. Or if the lifter had a machined top side, stand it up on a surface place and check the crown. You'll need tools that measure 0.0001". (better to use a V-block clamp on the lifter .. the top sides are probably not carefully machined). There are numerous articles on the proper ways to measure lobe taper and lifter crowns.

Typical lifter crown is about .002" ... cam lobe taper can vary from .002 - .004. I think the higher lift cams usually are on the upper end of that scale. If you have a lobe that is a bit low at 0.0015 ... and a lifter on that lobe that happens to be a bit low at 0.0015 they add up to a contact angle that is probably not sufficient for good lifter rotation.

Usually you don't have to measure every lobe, or every lifter ... you can get a feel for what specs the manufacturer is using by checking a couple of lobes and couple of lifters. What is perfect? I have no idea, I'm sure there is a paper on it somewhere .. but I'd start worrying if both taper and crown were not both 0.002 or greater.