OER Parts offers a wide selection of Dress Up Kits for your 1999 GMC C3500. OER Parts offers 1999 GMC C3500 Valve Covers, 1999 GMC C3500 Exhaust Manifolds, 1999 GMC C3500 Intake Manifolds, 1999 GMC C3500 Timing Covers, 1999 GMC C3500 Water Pumps, 1999 GMC C3500 Oil Pans, 1999 GMC C3500 Custom Under Hood Mirrors, 1999 GMC C3500 Radiator Support Show Panel, and more...