Rotating Axle, U-Bolts uneven

How do I rotate the front of the axle up?
I have a vibe at 25MPH - 35Mph, and I thinks it’s my drive shaft angle. I installed Dakar’s (with 3rd leaf removed) and OME N182's 3 weeks ago with no vibe. This week a put Radflo coilovers set to 2" on and now I have a vibe. I already put a CB drop in when I installed the Dakar's. But I am sure I read somewhere that one thing to check before I buy a shim kit is the U-bolt threads. I just checked and there is more thread showing on the fronts of the U-Bolts. If I wanted to rotate the front of the axle up how would I do this??? I figure loosen the u-bolts and tighten rears first but may be wrong. Should I lift the up for truck for this to let the axle hang?
Will this even work?
Thanks

 

i don't think there is any way to rotate the axle unless you install the shims? If you did the centering pin would not line up.

 

that wont work, the spring pad on the axle determines pinion angle. You need degree shims if you think thats what you need to do, but seeing as it didnt happen til the front was lifted, i'd say its due to the front lift and not the rear.

 

Ok thanks guys! Shims it is.
I don't thinks its the front, but I may be wrong.