"Loaded" pinion angle question

[MyOriginal66]

Loaded question cause I know the best way to do this is once the rig is together, fully loaded and at settled ride height. But that's not the case.

My 9" is being rebuilt and new spring perches are being welded on.

I'm running a WH 3.5" inch 11 pack spring with a couple springs pulled out, so more like a 3" lift. Should I build in 6 degrees, 4 degrees or none of additional angle on the perches?

 

[bronconut73]

I have 2.5" WH packs.
At first I needed 6° or so I thought. Now that they have settled out I see that I probably should have gone with the 4° shims.
If that helps....

 

[Broncobowsher]

Just order the housing with the perches tack welded in stock. Adjust and burn when done.

Too many variables. Position the transfer case back a couple of inches (trans swap) can easily change the angle.

 

[MyOriginal66]

I have 2.5" WH packs.
At first I needed 6° or so I thought. Now that they have settled out I see that I probably should have gone with the 4° shims.
If that helps....

Thanks. My axle is also pushed back an inch. I'm going to have him add 4 degrees. Seems like the "safe" bet.

 

[Steve83]

This is what Ford says about driveshaft angles on modified vehicles: