Chip, you got to write a book on your engine , be a best seller.This is gonna drive you to drink or consume large quanties of laughing tabacco, or both.
I would think cams are cast in lots, ground on production machines, one right after the other, I doubt the machine operator grinds each one on a custom basis, maybe someone here knows for a fact how they are made.It's a possibility that Howards has them made by a large cam grinder to their specs.If your cam is bad, then there must be a few others out there with similar problems.The stock distributer, whether it's Chevy or GMC, is free to float around a little ,unlike your mini HEI which is clamped down tight.Perhaps the stock type distributer won't cause a problem, they have about an 1/8 inch of up and down play on the drive gear as does the big head HEI found on 250 6 cylinder engines.You have eliminated the oil pump,oil pump retaining bracket as the problem, so the cam and dist are the likely suspects.
