Carter M4641 Mechanical Fuel Pump

Carter M4641 Mechanical Fuel Pump Overview

The Carter M4641 is a mechanical fuel pump built for OE-style fit, form, and function in classic carbureted applications. It is a direct replacement choice for select Buick, Oldsmobile, Pontiac, and GMC vehicles that use a 2 line pump or straight-port configuration.

With a cast housing, threaded inlet, inverted flare outlet, and a gasket or seal included, this pump is built around the core specifications buyers look for when replacing a mechanical fuel pump on vintage GM platforms.

Key Features

• Mechanical fuel pump design for carbureted fuel delivery systems
• Cast housing for durable underhood service
• Threaded inlet with inverted flare outlet connection
• Outlet fitting thread size: 5/8-18 UNF-2B
• Minimum flow rating: 30
• Minimum pressure: 7
• Gasket or seal included
• OE-style replacement coverage for select Buick, Oldsmobile, Pontiac, and GMC applications

Detailed Description

Carter M4641 is a mechanical fuel pump for classic GM vehicles that require a threaded inlet and inverted flare outlet setup. It is listed for applications such as the 1968-1980 Buick LeSabre, 1968-1972 Buick Skylark, 1973-1977 Buick Century and Regal, 1975-1976 Oldsmobile Cutlass and Cutlass Supreme, 1975-1976 Pontiac Firebird, and select GMC P2500 and G3500 models. The part number M4641 is also cross-referenced to select Airtex, GMB, and Spectra Premium numbers for the same application.

Carter’s fuel systems program focuses on OE fit, form, and function with broad vehicle coverage and problem-solving replacement features. For buyers searching for a mechanical fuel pump for 1977 Buick Regal, 1977 Pontiac Firebird, or 1979 GMC G3500 straight ports, this pump provides a specification-driven replacement option.

Common Problems This Pump Can Address

• Hard starting caused by weak fuel delivery
• Fuel starvation under normal driving conditions
• Low fuel pressure in carbureted systems
• Fuel pump leakage at the housing or connections
• Poor drivability from inconsistent mechanical pump output

Installation Notes and Tips

Verify inlet and outlet orientation before installation, especially on vehicles noted with straight ports or 2 line pump configurations. Confirm the 5/8-18 UNF-2B outlet thread size and inverted flare connection match the existing fuel line setup. The gasket or seal is included; mounting hardware is not listed as included. Always compare the original pump, line routing, and vehicle notes before installation on Buick, Oldsmobile, Pontiac, or GMC applications.

Quality Assurance

Carter builds this mechanical fuel pump to support OE-style replacement needs with premium fit and application coverage. The cast construction, included seal, and application-specific connection types reflect a replacement part engineered for classic fuel delivery service.