Listen to what Carl and Jerry says, make sure you have an axle that hasn't bent, caster wedges are needed.
Positive caster creates a lot of align torque (the force that straightens the steering wheel when you go forward) which improves straight line stability of the truck. If your truck does not have caster wedges between the axle and leaf pack then they have been removed and need to be replaced and positioned correctly to start off then continue your checks.

Last edited by sstock; 03/16/2019 2:45 PM.

1953 Chevrolet 3100
261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
In the DITY Gallery
Video of the 261 running

1964 GMC 1000
305 Big Block V6, sm420, the next cab off restoration