[tetstream]

I would say, replace your shocks. It's widely felt that the OEM GM shocks are junk, very soft and fail quickly. I replaced mine with Bilsteins at 500 miles. It gave the truck a more controlled feeling, and cured what I called "the bob", or the truck oscillating up and down from hood to tail. The ride is a bit firmer, but tire pressure makes more difference than the shocks.

Some guys have used the Rancho adjustables and like them.

Around the same time, I replaced the oem tires with Bridgstone Dueler Revos 265/75 16 E. That improved the control and ride.

Also installed HD sway bars front and rear, which really made a difference.

All in all, I am very happy with the way the truck handles now. It's not a supple 1/2 ton ride, but it IS very confident and sure footed. I would never go back to stock.

Shocks from Kennedy Diesel.
Sway bars from Frederico Racing.

Did both installs myself.