Found a 9 inch rearend complete from brakedrum to brakedrum with a 3.50 gearing this weekend and only 10 mile from my house. The amazing part is this thing was posted on CL for the last 2 weeks and for only $125.
Judging by the spring mount pads on TOP of the axle housing, the large wheel bolt pattern and the very long parking brake cables ... my money is on a F-100 pickup.
Deuce your on top of your game and right you are a 1970 F-100. Once cleaned up and rebuilt it's going in my F-1.
Make sure you take lots of pics when you do the swa!...I've been intersted in doing this swap myself.
Well, I had a little experience I installed a F-100 9 inch under my 48 F-1 about 30 years ago. They are almost a direct bolt in as I remember.