GM pump assembly to XJ tank - adapter ring

thingiverse

This guide explains how to install a GM truck fuel pump assembly into a Jeep XJ late model plastic tank, suitable for all LS swaps. After dealing with numerous aftermarket pumps, expensive filter regulators, and fittings that only led to problems, I decided to try something different: installing the stock GM truck pump and assembly directly into the XJ tank. To my surprise, it works flawlessly. For those considering an LS swap, this solution is by far the easiest and likely best option. You already have the GM pump and can from the donor vehicle; why waste money on aftermarket parts of questionable quality? Instructions: 1. Design and print an adapter ring using a fuel-safe material like PETG, aiming for 3 perimeters and 40% infill to ensure maximum strength. 2. Remove the XJ pump assembly and discard it. 3. Assemble the adapter onto the GM pump assembly, using both rubber gaskets from the GM and XJ pumps. It's a snug fit; a little spit or grease should do the trick. Make sure to place the GM lock ring between the top of the adapter and the XJ tank locking ring. 4. Remove the GM fuel sending arm if you're not using it. 5. Install the assembly into the tank, pushing down until it bottoms out. Measure the gap between the mating surface of the ring and the top of the tank (where you'll thread things on). This will determine how much to chop off the pump's legs. 6. Disassemble everything, cut off the legs to the correct length, reassemble, and then flare the ends of the legs using a regular flaring tool. 7. Install the assembly and run some cheap nylon lines with 3/8 and 5/16 quick connect fittings. You might even be able to reuse the lines from the donor truck; stick a cheap filter in-line somewhere. This approach costs less than $50, and you get to use an OEM pump that's proven to work for your application. Pro-tip: If you're swapping an LS into any vehicle, consider using an XJ tank. They're indestructible, affordable, easy to find, and fit almost anywhere. I'm running this setup in my LS-swapped, bobbed 95 4Runner truggy on Land Cruiser BJ/FJ60 axles; the GM tank is too big, while the Toyota tank is a subpar steel design that sits below the frame. The XJ tank fits perfectly just behind the rear axle and can withstand rough landings without sustaining damage.