If the truck has never or even recently been maintained----all the rubber biscuits are dryrotted and have no cushion or dampening capability left--spending money on any alignment/axle bending/ect will just be wasted dollars and lead to more frustation because it won't fix the problem/problems.
As already stated, lift the wheels off the ground and shake in all directions/planes---the cross links/idler arms/etc on those series of trucks were lucky to last any amount of time!

If the king pins/bushings are bad they can be easily repaired . replace the steering links/tie rod ends and all the axle mounting bushings along with a good set of heavy duty shocks--then have aligned and you can be confident that the job will last.

44 year old rubber is so worn out it probably won't even smoke/smell when you burn it