OER Parts offers a wide selection of Manual Transmissions & Parts for your 2004 GMC Truck. OER Parts offers 2004 GMC Truck Bearings, 2004 GMC Truck Boots, 2004 GMC Truck Complete Transmissions, 2004 GMC Truck Flywheel, 2004 GMC Truck Gaskets, Seals & Filters, 2004 GMC Truck Gears, 2004 GMC Truck Hardware, 2004 GMC Truck Shift Knobs, 2004 GMC Truck Shift Linkage, 2004 GMC Truck OE Shifters, and 2004 GMC Truck Performance Shifters.