These MSD Ford Blaster Coil-on-Plug ignition coil packs feature a patented winding design and direct bolt-in replacement. The improved spark energy and voltage of the coil packs, combined with their reliability, have made them a favorite of performance enthusiasts. They are designed as direct bolt-in replacement coils for many SOHC Ford V8 modular engines. The housing and installation are the same as the factory coils, but that is where the similarity ends. Inside the MSD coil packs, engineers used better quality materials to assemble the primary and secondary windings. The MSD Ford Blaster Coil-on-Plug ignition coil packs take the spark energy right out of the coil and put it across the plug gap to improve the combustion and output of the engine.