Billet Dual 4150 carb. or EFI throttle body to Enderle Hat or BAU Hat adapter for 4150 style (5-1/8 Diameter opening).13.25 hat bolt center. 8-5/8 center to center carb spacing. Adapter is 2" tall. If using edelbrock or holleys with choke housing you must use 1" air cleaner spacers. Comes with K&N drop in filter, mounting hardware and gaskets.