Hi everyone! I have a few dumb questions on the '73+ 4x4's, please excuse my ignorance.

1. Did the F100 4x4 frame get wider behind the cab or did it stay at the 34" like the F250 4x4 did until '77 1/2?

2. Same deal for the F150 4x4?

3. If the F100 4x4 did get wider, is the rear axle the same width as one in the F100 4x2?

4. Are the pinion angles the same for the F100 4x4 and 4x2 rear axles?

5. Did the F100/F150 4x4 rears get 31 splines or 28?

Thanks a lot for your help!

 

5) 4x4's should have 31 spline axles.
4) 4x4 should have a different pinion angle because they usually sit higher.
3) ???????????
2) ???????????
1) ???????????

Sorry, that is the only ones that I could answer.

 

I don't know exact measurements but the frames on the F150s from 73 to 77.5 were wider than the 250s, or more acurately the 73-77.5 F250's had a narrower frame than the rest. The axles themselves should be no different in width but the spring perches on a 73-77.5 F250 should be a little narrower than an F150 or a 78-79 F250. Perches can, of course, easily be removed and relocated and pinion angles can be adjusted at the same time.

Hope that helps.