OER Parts offers a wide selection of Manual Transmissions & Parts for your 1966 GMC Truck. OER Parts offers 1966 GMC Truck Bearings, 1966 GMC Truck Boots, 1966 GMC Truck Complete Transmissions, 1966 GMC Truck Flywheel, 1966 GMC Truck Gaskets, Seals & Filters, 1966 GMC Truck Gears, 1966 GMC Truck Hardware, 1966 GMC Truck Shift Knobs, 1966 GMC Truck Shift Linkage, 1966 GMC Truck OE Shifters, and 1966 GMC Truck Performance Shifters.