Fast Coil, Xr Series For 99-07 Gm 4.8/5.3/6.0 Light Duty Trucks With Round Delco Coils

XR Series ignition coil for '99-'07 GM 4.8, 5.3 and 6.0 trucks provides up to 15-20% more energy over stock ignition coils.Built from ultra-pure copper alloy windings, our coils have been tested to 8,000+ RPM and 1,500 HP.