This billet adaptor is used to install any Autolite, Holley, or MotorCraft 2V carb on a stock SMALL LOG cylinder head with a 1.5" carb bore. The adapter comes with a custom billet insert, which improves air flow and horse power, and two stainless steel Allen head cap screws for mounting (carb studs and phenolic spacers are optional). Gaskets not included. No machining required.