OER Parts offers a wide selection of Brake Components for your 1966 GMC 2500. OER Parts offers 1966 GMC 2500 Calipers, 1966 GMC 2500 OE Calipers, 1966 GMC 2500 Performance Calipers, 1966 GMC 2500 Front Calipers, 1966 GMC 2500 Rear Calipers, 1966 GMC 2500 Anodized Calipers, 1966 GMC 2500 Powder Coated Calipers, 1966 GMC 2500 Wilwood Calipers, 1966 GMC 2500 4-Piston Calipers, 1966 GMC 2500 Aluminum Calipers, and 1966 GMC 2500 Cast Iron Calipers.