At this point no one really cares what GM or Ford said, its information that does not apply to any motor on this site. Very few rebuilt engines use factory parts, so what the factory guys tell you only applies to there parts, assembled in there shops, using there oils and break-in practices.
You really think when your Crower, Comp, Lunati, Howards Cam (or any manufactorer) fails, they will stand behind it when you used some other companies advice or oil not recommended by them? Good luck with that!
Call the guy that built the motor you are working on, thats the bottom line, everything else is hear say and opinions. Every year since forever, oil has changed formulas, so why bring up old data?
Jon was right on the money, THERE IS NO PERFECT ANSWER !
Joe
