1997 chevy blazer 4wd 2dr 4.3 engine ls package

check the front torsion bars for play or slack, these trucks love front balljoints check them with the truck jacked up under the control arms with a prybar lift the wheels up and down , also the rear diff torsion arms and the rear springs for broken leafs, also could be a camber/caster issue you may have the allignment checked please rate this -jeff