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Hey guys,
I finally got my 9 inch rear end installed and all bolted up. I read in the How Tos link that the spring perches are already in the correct location and don't need to be moved. I used a 1970 F100 9 inch and after its installed, the pinion points upward slightly. I have read other articles pertaining to drive shaft phasing that the pinion and trans tailshafts need to be parallel to each other but the tailshaft needs to be a few inches higher so that the u-joints will work properly. Has anyone relocated their perches to bring the pinion parallel to the ground? I am thinking that as long as the driveshaft is not perfectly straight fromt he tailshaft to the pinion, then I will be ok. Am I offbase on this?
Isn’t the 1970 too wide for the monkey face? In ’65 when Ford went to the twin I-beam they increased the track width?
The trans output should be 3 degrees downward (built into the intake manifold, carb base level then the trans is 3 degrees down automatically) and the pinion yoke 3 degrees up. Side to side offset doesn’t matter.
No OldF1, the swap is good up thru 72. 73 is when they got wider - about 3" more.
I made the adjustment by using 5 deg caster wedges. I believe they now call them tapered shims. NAPA sells them in a variety of widths - 2" is just right for your app. Last ones I bought they showed only 4 deg as the max they carry.
That gets the pinion close to where it needs to go. It can be off a little and still work fine. As OldF1 said the trans is down about 3 so the pinion needs to point up 1-5. Your mileage may vary.