Base gasket for Mercruiser TBI adapters and Mercarb marine carburetors. Mercruiser 2 Barrel Carburetor Mounting Gasket | Barr Marine MC47-27-70143 Barr carburetor mounting gasket Fits various Mercruiser 3.0L, 4.3L , 5.0L, 5.7L and 350 MAG engines with Mercarb carburetors or TBI adapters Replaces Mercury 27-8079821, 27-70143-1