What kind of shocks are you running??? No rear shocks can be dangerous. If you want a better ride step up to a good monotube shock like the bilsteins or edelbrock or rubicon or skyjacker platinum or........
What you are probably seeing is that there is little weight in the rear of the truck and your current shocks are valved too stiff. If you aren't into more expensive shock that can be custom valved for your application, you can try angling the shocks inward. More angle effectivly allows the shock to act like it has a lower pressure valve. You will however, lose some roll control.
