LS EFI In-Tank Sending Unit and Fuel Pump for G-Body
When planning an LS conversion in your G-Body, reliable fuel supply and accurate gauge readings are essential. The EFI Sending Unit and In Tank Fuel Pump installs into the factory tank flange, eliminating adapter plates and preserving shell integrity. A 3/8" sending unit preserves stock float resistance curves during cornering or acceleration, while the Walbro 255 lph pump delivers consistent high pressure for up to 550 hp under load. Compatible with Grand National, Monte Carlo, Cutlass and G8 tanks, this assembly requires minimal modifications and retains original seals and fuel line routing.
Product Overview
The EFI Sending Unit and In-Tank Fuel Pump for G-Body is engineered to convert the original G-Body fuel tank into a modern electronic fuel injection system tailored for LS powerplants. By replacing the stock tank internals with a complete assembly, you gain precise fuel level feedback and a high capacity pump all in one package. The sending unit retains the factory gauge interface so you keep your dash readout without any calibration hassles. This focused approach ensures that the upgraded system mimics OE functionality while unlocking the performance potential of EFI.
Seamless Installation and Compatibility
This kit fits GM G-Body applications exactly, including Buick Grand National, Chevrolet Monte Carlo, Oldsmobile Cutlass, and Pontiac G8 tanks. No universal adapters are required, enabling a direct swap into the existing tank with minimal drilling or trimming. The 3/8 inch feed line is preassembled with a quality sending module that aligns with the stock gauge connector. By working precisely to the factory mounting pattern, the unit maintains proper pump submersion and prevents airflow from entering the fuel rail. The design focuses on a straightforward retrofit so the install time is cut dramatically and fitting errors are eliminated.
High-Flow Pump Performance
At the heart of this assembly is the Walbro 255 liter per hour fuel pump capable of supporting up to 550 horsepower on LS engines. This pump delivers stable high pressure under steady load, crucial for modern electronic injection that demands consistent flow to match engine demand. The elevated flow rate ensures that fuel supply remains constant during hard acceleration, cornering, or high speed runs where stock systems might fall short. By providing a robust margin over typical EFI requirements, the system is well suited for both street sorties and track duty.
Reliability and Service Access
Constructed from corrosion resistant materials, every component in the tank module is selected for durability in a challenging environment. The assembly seals tightly against the tank opening to prevent vapor leaks and maintain system pressure. When routine service is needed, the modular design allows for pump and filter replacement without removing the entire tank. This simplifies maintenance intervals and keeps downtime low. Whether you are upgrading a street cruiser or a performance build, this sending unit and in-tank pump combination delivers a future-ready fuel supply that meets the exacting demands of modern EFI.
To complete your EFI setup with reliable flow, consider our Related FLT product Fuel Fitting Kit for G-Body.