The rear end I have right now is out of a 1965 Ranchero with a 289 2V. It has a 3.20 or 3.25 ratio for sure. I checked it by hand. I wanted to know the ring gear size. 7.5",8", or 8.8"? Any help would be appreciated. Thanks.
Tim

79 F150 4x4 410m Built Ford Tough!(9.1:1,KB pistons,custom Comp Cams X-Treme 210/218-.508/.524,roller rockers)/c6/3.5:1 gears,4.11:1 soon, Demon 4bbl, 285/75R16 BFG Mudders on alumn. mags with New Drk. Blue paint.
65 Ranchero 170-6, 3on the tree, solid mags, New Bright Yellow paint

 

My V-8 65 Ranchero had an 8 inch Ford. It also had a close ratio T-10 4-speed, and boy was that thing fun to drive.

 

If the back of the housing has a "bump" in it - to allow for clearance of the ring gear - it is a 9". If it is just smooth - it is most likely an 8" although some very early 9" units were smooth, but I believe that was in the late 50s.

Hope this helps

 

does it have a rear inspection cover? if so it aint a 9 inch. the 7.5 inch was not used behind v8 engines.