[LONGHAIR]

Originally Posted by westofb

. When rounding a corner, the steering wheel does not want to self center as it should, you actually have to turn it a bit to get it go back to center. I used the term "bump steer", actually the truck just tends to wander a bit over rough spots in the road.

These are 2 differnt things.
First, the steering wheel not re-centering is a caster issue. You are probably lacking "positive" caster. This not only straightens the wheels after a turn, it aids in high-speed stability.

"Bump-steer" is a "geometry" issue of the travel arcs of the supension itself and the ralationship of the steering parts (outer tie-rods). If these arcs of travel do not "work together" the wheels "toe out" (or in) during suspension movement. As the "toe" changes, the vehicle "wanders" trying to follow which-ever tire is "dominant". It is not really and alignement issue. The alignment could be "dead on" and still have bump-steer problems.

This could very-well be at leat part of your problem. You stated the the track width had changed, but those pivot points have not....But an inch of difference from the upper to lower arms sounds like a lot, for no more than a single coil cut from a stock spring? There must be some issue caused by the mixing of the 1/2 and 3/4 ton parts?

It would be really good to see a picture of the front suspension at ride height.