12 bolt rear question

[jhyder408]

so I bought this '67 long bed c10 for the bed and front clip. I am parting out the rest. I looked at the glove box door and the data plate said
posi-trac 4:11r. I jacked up the rear, marked the tire and marked the pinion. turned the tire one full revolution and the pinion spun a little past 4 turns. I inspected it, looks like it has never been out of the truck. I posted it on craigslist and had it sold in a bout a week. I went and pulled it out, which was a pain by the way, my theories of it never being out was correct by the way the u bolts being such a pain. Now to the point, the guy that bought it said when he got it home and checked it, said it was a 3:73 posi not 4:11.
This has been bothering me, I am not a scammer especially when selling parts. And I just think he is wrong.
SO, anybody have any thoughts on the matter???