My truck handle like a dream since I replaced the springs and the shocks. Next step will be radial tires.
Lowering your truck (dropping the body/frame relative to the axles) will not make it handle better, it will make it worse because it upsets the steering geometry.
Your springs are almost certainly going flat, which is probably a big part of your problem.
So for excellent steering and handeling I would recommend:
Adjust your steering box correctly.
Check and adjust or replace your tie rod and drag link ends.
Make sure your king pins are in good order.
New springs and shackles
New shocks
Get the truck aligned correctly.
And for gravy,
Get radial tires. Keep your old rims and either spend the big bucks for the Cocker 6.50 R 16 or get the tallest skinniest radial that will fit correctly.
I think you will be very pleased, the truck will handle better than new and will look great too.
I have done all the above except the radials, and I am flat amazed at how good she handles. Still a truck of course.
Kurt