I have noticed this for many years now that people with a 9" Ford rear end will say they have a 3.73.. I have never seen any gears in that ratio sold by anybody.
Just 3.70
Ford 7.5" & 8.8" have a 3.73 though.
Chevys have 3.73 available on most all car/trucks.
Dana 60 & 70U have 3.73 available.
Just curious.
