The Selectors plug into the retard module receptacle of any MSD Timing Controls. 1964-chevrolet-biscayne-esi2503226 188 in Thick - 1-Piece

188 in Thick - 1-Piece - Steel Core Rubber - Small Block Ford - Set of 5

Main Bearing - Race Series - Standard - Extra Oil Clearance - Coated - Big Block Ford - Kit

Note: This system eliminates the Factory Exhaust Valves and provides "Dummy" valve stands so the Factory Acutators still work without throwing off a code

Engine Oil Pan - Street / Strip - Rear Sump - 6

Header Mount - Wall Mount - Aluminum - Black Powder Coat - Kit

The Selectors plug into the retard module receptacle of any MSD Timing Controls. 1964-chevrolet-biscayne-esi2503226 188 in Thick - 1-PieceThe Retard Module Selectors allow you to select between 12 retard amounts with the turn of a dial.