I think the three biggest things that made the best improvement in my trucks ride were the shocks, front sway bar and alignment. I'm not sure if you can find a shop that has the ability but heres a thread I posted on the best way to get the best alignment. Even if their machine doesn't have this function its still the best and only way to do it as far as I'm concerned.
http://67-72chevytrucks.com/vboard/s...d.php?t=582187