REV Ignition High Performance Ignition Coil Set of 8 GM Square Type Coil 12558948 1997-2005 5.7, 7.4, 8.1 Please look at product description for complete list of compatible vehicles. Before you order, make sure these coils are the same shape as the coils you are replacing! Our High Output Performance coils give you the bonus of 10-15% more spark for improved performance. They are designed to install with no modification required to your vehicles wiring. Improved Throttle Response, Improved Gas Mileage, Reduces Misfire 100% Copper Wire Assembly, Each Coil Factory Tested, Quality Guaranteed Compatible with OEM numbers: UF192, C1144, 12556450, 12558948, 392881732, D580