GM-GMC: 4.3 crank seal, true thanks, gm

Question
I have been told that the factory crank seal[later model at least] is inferior and prone to leakage. Is this true?  Thanks   Gary

Answer
I do not know about the seal leakage rumor.

I do know that I have the same kind of seal in my van, which has a GM crate 6.2 L diesel short block that sat for ten years before I installed it.  It has the one-piece rear main seal and I have no problems with it.  I did not change the seal before I installed the short block.