It's probably me misremembering what he said when I picked the car up, then. I do remember him saying something about not being able to find the right speedo gear, thus the incorrect speedo reading.
But that still begs the question of whether the car came from the factory with 4.10 posi or not. Joe said he was the third owner, and it didn't sound like the car had been substantially tinkered with before he bought it (still had the EFI unit at that point). Knowing whether it could have come that way or not is more of a curiosity on my part, kind of like doing an archeological dig.
es