Chrysler Big Block Fuel Pump | Sierra 18-7255 Carter style mechanical fuel pump for Chrysler M400 & M440 marine engines from 1976-present. Used on Chrysler big block marine engines with vent tube to carburetor Includes mounting gasket Use kit p/n 3744265K if converting from old style fuel pump without vent tube provision Replaces original Carter pump with flange ID 6767 & M6767 Replaces 3745415, 3744265 Replaces Mallory 9-35401