OER Parts offers a wide selection of Coils for your 1966 GMC 2500. OER Parts offers 1966 GMC 2500 OE Quality Ignition Coil, 1966 GMC 2500 Replacement Ignition Coil Premium Quality, 1966 GMC 2500 HEI Ignition Coils, 1966 GMC 2500 Chrome Ignition Coils, 1966 GMC 2500 Zinc Plated Ignition Coil Bracket, 1966 GMC 2500 Ignition Coil Resistor, and 1966 GMC 2500 Chrome Ignition Coil Bracket & Chrome Coil Cover.