G-Body EFI Fuel System: Tanks Inc. Tank, Pump, And Sender

The G-Body is having a moment. Whether you pulled one out of a field or scored a clean one off Facebook Marketplace, more builders are doing it right the second time around by swapping to a G-Body EFI fuel system. If that describes your situation, Tanks Inc. has already done the heavy lifting. They offer a complete lineup of hardware built specifically for the 1978-88 GM G-Body, and it all works together as a system.

Fitment spans the Chevrolet Monte Carlo and Malibu, the Buick Regal, Century, and Grand Prix, the Oldsmobile Cutlass, and the Pontiac Bonneville, Grand Am, Grand LeMans, and LeMans. If you are running one of those cars and planning an EFI conversion, here is what Tanks Inc. brings to the table.

The G-Body EFI Tank

The foundation of any G-Body EFI fuel system is the Tanks Inc. GM G-Body EFI gas tank. It holds 17 gallons and measures 36-1/4 inches by 24-1/4 inches by 8-7/8 inches. Tanks Inc. builds it from galvanized steel and finishes it with a powder-coated silver exterior. It looks close to an OE tank once it is in the car. The install requires no modification to the vehicle.

The tank uses a two-piece neck design that connects with a supplied 2-inch ID rubber hose. Inside, Tanks Inc. builds in EFI-style baffling with an extra-large 4.8-liter dual-tube baffled fuel tray. That tray is the key piece. Hard acceleration and cornering can uncover the fuel pump pickup and starve the pump without proper baffling. The tray prevents that. The fuel pump and sender recess into the tank, so everything sits out of the way with no trimming required.

The tank accepts GPA series fuel pump modules from Tanks Inc., available in flow ratings from 109 to 450 liters per hour. It also accepts aftermarket five-bolt senders in multiple ohm ranges, so it works with a factory 0-90 ohm gauge or an aftermarket unit. If you run a tube sender or a reed sender, the length is six inches.

Tank Straps

Tanks Inc. offers a matching set of tank straps for the 1978-88 GM G-Body. The set includes two straps at 37-3/8 inches each, finished in black E-coated steel. Fitment covers the Oldsmobile Cutlass, Buick Regal, Century, Chevy Monte Carlo, and Malibu; Pontiac Bonneville, Grand Am, Grand LeMans, Grand Prix, and LeMans. Sourcing the straps at the same time as the tank keeps you from chasing a measurement later.

GPA Fuel Pump Module

Tanks Inc. builds its GPA series fuel pump modules around Walbro (TI Automotive) high-performance pumps. Walbro supplies products for two-thirds of the vehicles produced around the world and brings strong hot-fuel handling to the table. An internal bypass channel improves recovery from aeration compared to competing pump options. The GPA module supports applications up to approximately 1,000 horsepower, depending on the pump selected, so there is room to grow if the build heads that direction.

Tanks Inc. mounts everything on a heavy 10-gauge no-warp plate with yellow-zinc plating to prevent corrosion. The module includes 1/4 NPT supply and return line fittings, a barbed vent fitting, oven-brazed fittings rated to up to 100 psi, and an in-tank wire harness. The internal wiring harness, supply line, return line, filter sock, and insulator sleeve all ship with the pump. The gasket and screws ship with the tank. The GPA module mounts into the factory-installed reservoir trays in Tanks Inc. tanks.

One note worth flagging: these are gerotor-style pumps and will not work with Pulse Width Modulation. Running a FiTech system requires turning off PWM before using this pump. Tanks Inc. provides instructions for that on their site.

Fuel Sender Options for Your G-Body EFI Fuel System

Tanks Inc. offers two sender types. The first is their standard five-bolt swing arm sender. It mounts with five screws and works on tanks from six to 24 inches deep. Cutting the float arm to length uses the included instructions. It works on all 6-24 volt systems with positive or negative ground. Tanks Inc. builds it around a high-quality ceramic board rheostat and offers it in several ohm ranges: 240-33 ohms for standard aftermarket gauges, 10-180 ohms for VDO gauges, 0-30 ohms for GM applications up to 1964, 0-90 ohms for GM 1965 and up, 73-10 ohms for early Ford and Mopar, and 16-158 ohms for Ford 1987 and up. This sender does not include a fuel pickup tube, which some original senders have.

The second option is the floatless tube sender. Tanks Inc. designed this to solve the erratic gauge pointer movement that the rotating float arm and resistance card setup can cause from fuel slosh. The tubular design acts as a dampener, so the gauge reads more smoothly. No moving parts means nothing to wear out. The sender works with gasoline, diesel, oils, and many other fluids. It mounts from the top using the standard aftermarket SAE five-hole mounting flange and ships with a neoprene gasket and mounting hardware. Note that senders 15 inches and longer are non-returnable, and some sizes take three to four weeks to ship. The floatless sender fits anywhere a conventional swing arm will not clear.

Both sender types come in the same ohm ranges, so matching to your gauge setup stays straightforward regardless of which design you run. If the G-Body in your garage has been waiting on a reason to get back on the road, a proper EFI fuel system is a solid place to start.