Mark, the biggest factors I have seen are the metallurgy of the lifters, taper on the cam lobes and of course lubrication. You must use a good break-in additive and a suitable oil afterward.I doubt that metallurgy of the camshaft is a problem because there are only a couple of sources as long as it is a US cam core.
Most of the failures I have seen in the last 10 years were insufficient taper on the cam lobes. This will cause the lifter to slide on the lobe instead of rotating.
We are using Gibbs XP8 in our race Y. It is recommended for no more than .0025" bearing clearance.
Gibbs has lots of oils and lots of people are using Brad Penn.
http://ford-y-block.com 20 miles east of San Diego, 20 miles north of Mexico