A front sway bar is the cheapest suspesnion mod (that really works) for your truck.
It will drive and handle so much better.
You can find them on some 67-72 and 73-87 trucks for cheap.($50 or less)
Add a set of good polyeurethane bushings from Energy Suspension and bolt it on.
Up front,... since your truck is so low,... you can bolt the bar directly to the frame rails.
The oem set-up had a set of metal brackets riveted to the frame to lower the bar down on stock height trucks.
ECE also makes a "lowered truck" bracket, that I have used many times,... but I don't think they are neccessary.
These sway bars come in 1-1/6", 1-1/8" and the biggest 1-1/4" (usually found on 3/4 ton trucks).
Get the biggest bar you can find.
You won't regret it.
Here's a good thread:
http://67-72chevytrucks.com/vboard/s...ad.php?t=72338
Another advantage to the Energy Suspension bushings,... they come with the metal brackets to mount them.
You can buy them in a "greaseable" version also.