Upon digging through the glove box of the used F-350 I bought, I found a receipt for what looks like a rear-end repair job. I'd like to know what the gear ratio is for the gear set listed. Best I can tell from the hand-writing, the part number is F81Z 4209. Two more part numbers that may help are: F2TZ 4B409 and F81Z 4026.

The original sticker was also in the glove box, and the truck was factory fit with a 4.10 ratio. Just trying to figure out if this was a repair, or a modification.

Thanks,