OER Parts offers a wide selection of Brake Components for your 1989 GMC R2500. OER Parts offers 1989 GMC R2500 Calipers, 1989 GMC R2500 OE Calipers, 1989 GMC R2500 Performance Calipers, 1989 GMC R2500 Front Calipers, 1989 GMC R2500 Rear Calipers, 1989 GMC R2500 Anodized Calipers, 1989 GMC R2500 Powder Coated Calipers, 1989 GMC R2500 Wilwood Calipers, 1989 GMC R2500 4-Piston Calipers, 1989 GMC R2500 Aluminum Calipers, and 1989 GMC R2500 Cast Iron Calipers.