With the Avalanche available in both a 1500 (1/2 ton) and 2500 (3/4 ton) versions the suspensions are completely different. At Jack-it we offer a variety of lift kits for both models.  These kits range from smaller 2 inch kits up to large 7.5 inch full suspension systems.   For those drivers wanting to really improve performance check out the BDS or Rough Country coilover systems.  These kits will allow for much larger tires while improving off-road on highway driving conditions.