the latest i've read was an article by Ed Preston, he sez the new SN oils can actually wash off any "zinc" on the cam and lifter and wear lobes on broken-in cams in 5-15k miles.
The API test engine is a 3.8 Buick V6 with less than .375 cam lift and 215 spring pressure.

My \'64\'s in the Gallery
Pictures in my Photobucket
1964 C10 Custom Cab 350/700R4
1964 Suburban 350/700R4
1979 Ford F350 4x4 400/c6