Fuel Pump GM Small Block | Sierra 18-7274 GM Small Block Fuel Pump | Sierra 18-7274 AC style mechanical fuel pump for GM 305 & 350 cu. in. marine engines marinized by Mercruiser & OMC. Fits Mercruiser GM V8 305 & 350 cu. in. marine engines Replaces AC pump with flange ID 41421 & Carter M73021 Includes mounting gasket Replaces Mercury 86246T, 86246, 78485, 71646 & 86246A1 Replaces OMC 509409 Replaces Carter M73021 Replaces Holley 716-41421 Replaces Mallory 9-35417