Not officially, I've searched through the workshop manual just now and I can't find anything set in stone. I think an engineer told me before that a difference of half a degree or 1 degree may induce a low speed driveline vibration in these trucks.

 

The shackles work the same regardless of whether the truck is two or four wheel drive. My opinion, lifted 2WD trucks on stock rollers look ridiculous. I'm in the "lower a 2WD, lift a 4x4" camp.

 

lowered mine by taking out the factory spacers. I had an iron worker at work fabricate a bump stop to fit in. had to add spacers on the u bolts until i get a set from a 4x2. with the SWB reg. cab i have no vibration (15000 miles) since droping the rear.

 

i agree