This is from the 1965 Comet-Falcon-Fairlane-Mustang Shop Manual, telling you how to set up the Ford 8 and 9 inch rearends. Enjoy! (the material is for both, except where it says except 289 HP which means 8, and with 289 HP which means 9)
And some pages from the 1979 manual showing how to overhaul the 9" traction-lok differential
and here is a general rearend gear setup guide from Yukon Gear, in pdf form
