Hi all I have a 9inch rear out of an 82 f-150. Here is the info off the tag first line (WDM CN 1K27) second Line (3 50 9 S318B). A kind person on this forum decoded it to this. WDM CN Bronco '80-'82, F150 '79-'82.
3.50 ratio. Non-limited slip. 31 spline axles. 9" ring gear. The second line of the tag starting with "3 50" also indicates 3.50 ratio without limited slip. Now I have been on Randys Ring and Pinion today and here are the parts I think I need to do a complete overhaul. Part number YK F9-A-SPC for the kit and (for some reason the hyperlink didn't work). ZG F9-350 - CROWN,PINION,RING,RING PINION,CROWN PINION,CROWN WHEEL,FORD,DIFFERENTIAL,FORD 9,MUSTANG,GEAR - USA Standard Ring & Pinion gear set for Ford 9.0 in a 3.50 ratio. USA Standard Gear offers a lower cost alternative to other manufacturers when for the ring and pinion. I was going to buy the bad shoe production dvd to use it as a referance. Thanks for everyones input!

 

Ford 9 Inch Rebuild/Gear Setup .: Articles Have a read here, may help.