I agree 100%. Basic machining procedures are not hard to follow, regardless of brand (contrary to popular belief, the engine does not know what brand it is).

What is remarkable is the fact that certain technology trickles down from Pro Stock and Comp and some engine builders want to incorporate that crap into bracket engines. While most builders shy away from tunnel rams, roller cam bearings, 1200 plus pound valve springs, aluminum rods and rings with no tension they are quick to adapt incredibly tight tolerances and things of that nature. Not considering that PS has coated everything, impressive oil control and relatively short strokes.

It seems if you stuck a valve I would want to measure the ones that didn't stick. Slow timing is a guaranteed stuck valve even with .005 clearance on it. I would also want to measure the bearing clearances as well. Long stroke/short rod combos tend to make the crank flex and bend (Dart is working on LS blocks with bigger mains to increase overlap to stop some of the flexing issue) and maybe MM thought more clearance was appropriate for you application.

Also as a last thought......guys trying to run what I consider low oil pressure are doing the most damage to roller lifters, scuffing pushrods and grabbing bearings. I would rather have 50 at idle than 20. But that is me.

I think keep what you have, take some time off and regroup. this kind of thing is as bad for our hobby as is unavailable parts and crooked suppliers. Trust your gut. Most times it's right.