The James Duff 3 1/2" Ultimate Suspension System is a mostly complete system.

You should be aware of a few things:

The instructions are a bit vague, I Guess they expect us backyard mechanics to have more brains than me (Not saying much). In any case, they fail to mention that the front shock driver’s side must be mounted on the outside of the weld on tab. The instructions even show on the drawing it being mounted on the inside (Click Drawings at the right). When mounted on the inside it WILL hit the tracking bar drop brackets causing erratic steering and high-speed chatter and hopping. Not to mention the fact that it trashed a $32.95 shock almost immediately. (If you bought their new system where both shocks are located behind the front differential, this will not be a problem.)

I must admit after removing the severely dented shock to replace it, it still worked!

Also they send the front and rear pairs of shocks without stating which part numbers are intended for "Front" and "Back". (Tip the longer ones goes in front.)

The last thing they leave out is the fact that on the 11-leaf rear spring packs one of the spring eyes the second leaf wraps around the eye (unlike your stock ones). This eye with the wrap around second leaf should be located to the front spring hanger (toward the front of the vehicle). 

After installation of the 6° C Bushing the caster was still measured at -4° caster. I considered their radius arm drop brackets but changed my mind after I went through some U-Joints on the front drive shaft. I upgraded to Duffs heavy-duty shaft because I replaced my back one about 2 years ago and I love it.

One thing I learned is that your tires wear is very important. Recently I had my tires rotated and one of the fronts had 1/8" less tread, I could barely handle the truck at speeds over 50mph, changed it out and it was back to normal.