[A26B]

Originally Posted by 1989ZR1#74

You are correct. Only theories, but it "appears" that an LT5 could have been stamped with a VIN deravation and then not installed in that same sequence numbered ZR-1.

I don't think so and don't mean to imply that possibility. The 1st engine had the VIN stamped on it at BG & put in the car. When the 1st engine was removed at BG, another, un-stamped engine was taken from inventory at BG & then stamped with the same VIN at BG, making it the 2nd engine & put into the car. In essence, both engines would be, for all practical purposes the correct engine for the car.

I guess I would ask what if that crate motor was sent back to BG what would the VIN stamp look like?

By "that crate motor" you are referring to the 1st engine that became a crate motor after the 2nd engine was installed. I think the engine went to GM warehousing stock and not to BG after leaving MM.

What was the reason that the 405 LT5 was not installed in the correct ZR-1?

I believe there are 2 correct engines for the subject ZR-1. The 2nd engine which is in the car now & correctly matches the car VIN, and the 1st engine which ended up being a crate engine with a VIN. I'm guessing the 1st engine VIN should have been stamped out at some point after it was replaced.