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Started my 6.0 4l80e swap a couple of weeks ago. I have question about fuel tanks and pumps.

Donnner vehicle is 2001 GMC K3500 69k
6.0l motor/ 4l80e trans/ manual shift transfercase
have complete with PCM and wiring harness


I bought a 20 gallon fuel tank out of a 2000 TJ last week thinking I could use it for my rear fuel tank It came with a returnless fuel pump which I cant use. So I'm on Amazon looking at fuel pumps with a return I put a couple in my cart so I can look a specs. Well the wife gets a couple things from Amazon and orders both pumps. My question is those pumps for the 40 to 45# spec from the Jeep. That 6.0 wants 55 to 60#. Does anyone know if there's a
Jeep fuel pump that would give me that kind of pressure ? Or do I just go with a rear Chevy Blazer tank and sending unit?*

I’m not sure about the tj gas tank. My concern is that it might be a little tall and will hang below the frame rails too low. It will probably be fine but I’m not sure. I don’t know how high the floor of the wagoneer is in relation to the frame rails. I have a j10 with a 5.3 4l60 and am currently running an s10 blazer gas tank with the stock blazer fuel pump and it works well. I haven’t seen anyone put a tj gas tank in an fsj at all. Have you test fit it or held it up to the underside at all to see how it will fit?


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The pump part is easy. Install a GM pump in the Jeep sender assembly and bypass the pressure regulator. Add a bulkhead fitting to the tank or the sender for the return line. It works well and you get the nice sump of the factory TJ sender assembly. If I remember correctly the TJ tank is about 10” tall. It may hang down some, as to how much is too much is up to you.

I would think a TJ tank would be fine, though it's kind of a weird choice (since you didn't initially have it on hand), as the S10 tank is widely regarded on the FSJs to be the cheap, easy bolt-in tank.

As far as the returnless vs return style, you can get around that. The 2001 6.0s have a regulator on the fuel rail with the return line, you can also have a regulator in the tank (returnless style) and just cap or plug the fuel rail return line. But unless you plan to adjust the EFI tables for that I would stick with Yeller's plan. The fuel rail regulators are adjusted by intake manifold vacuum but the in tank regulators are not. So the PCM adjusts the fuel injectors to add more or less fuel based on manifold vacuum. If you convert yours from return style to return less, keep that in mind.

Get any of the GM pumps, and make it fit into the TJ sender with the output line going straight to the fuel rail i.e. bypassing the TJ in tank regulator and then get a bulkhead fitting for your return line.

Perfect idea guys! I'm gonna put a GM pump in the sender for that TJ fuel tank. I thought i would try a TJ tank 1 being I got a good deal on it 2 Being the dimension's are roughly 30x20x10 & 3 the fuel filling hoses are the same as the OEM side mount tank. I'll post my pics when i get closer to mounting it