trying to keep it on the road

['68 K-10]

The truck does fine on smooth flat pavement its when i hit a bump or get on a road that has grooves from the heavy semi's that it jerks left or right. it sounds like i need the cross over but i only take it in the sand or on the road there's not much rock around here and it doesnt see much mud so is it worth it? everything seems to be tight underneath. The sway bar bushings are a little wore out so that might make a little difference. i was told that if i lowered the sway bar that would help, any ideas on that? will the crossover steering correct the problem on the grooved road with the wide tires? Thanks for all the help guys.