Well I bought the trans, driveshaft and read-end. The rear-end is 3.73, when I bought it I was going by the tag matching a list saying it was a 3.76 first gear and a .72 OD. When I got it home and was cleaning some of the crud of I noticed how the tail housing and the gear case had different date code stamps. Tail was 88 and gear case was 91 and there was red gasket stuff where it was put together. It spins smooth and shifts good by hand but I was now wondering what gears were actually in it. I seen an article on checking what gears were so I did that by marking the input and output shafts at 12:00 and spinning the output CC and counting revolutions. Seems I have a 4.03 first and a .86 OD So 4.03 X 3.73 = 15.03. and what does this tell us? I found a neat calculator on the Spicer gear site
https://spicerparts.com/calculators/engine-rpm-calculator
