Hey Ralph, thanks for the encouragement. It's definitely needed lol.
So, I spoke with Jim at MM this morning. He finished putting the head together this morning and it is shipping out tomorrow ASAP. It should show up in time for me to take this coming friday off to do the install. He also decided to go ahead and convert the head over to a 33mm lifter setup at no charge to me, which is 25 grams lighter per lifter assembly than the stock 35mm lifters. He said that his experience shows this setup to be a lot more reliable and easier on the cam lobes since you can run lower spring pressures. The BIG delay here was with Web Cams, which apparently is pretty backlogged with work orders. Anyway, all of the old Ferrea single springs are gone, replaced with MM's proven OEM style dual spring setup, so I feel a hell of a lot better about this engine now.
He also recommended that I run BMW/Castrol 10W-60 synthetic motor oil which has been dealer-specified for 2000-2011 M-cars. It apparently offers the best engine protection that you can get, period. While M1 15W-50 is also good, it sounded like an oil life study he ran indicated that the Castrol 10W-60 performed better than Mobil 1 by a factor of 3x, and M1 15W-50 was already like 10x better than most other stuff. Holy crap, the 10W-60 is expensive though! For a stock M42 it is probably a non-issue since the cam lift is relatively low and they don't run up the edges of the larger 35mm lifters. In my case, the high lift on the cams means that the lobes overrun the lifter as they are ramping up, which was not an issue pre-2008 when most oils had higher zinc and phosphorus levels in them. After 2008 the EPA mandated some changes that caused most oils to have significantly reduced protection for high pressure assemblies, like directly actuated hydraulic lifters. It sounds like the performance cam industry has been reeling from this since the lobes get chewed up pretty bad in high lift applications. Mobil 1 15W-50 synthetic has some of the highest zinc and phosphorus (ZDDP) levels you can get in a non-race oil and it is still very good. For a very high performance engine where stresses are higher, it sounds like Castrol 10W-60 is the go-to choice though.
