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LM4 5.3L and 4L60E swap into 2004 LJ


I planned to get some work done yesterday, but ended up going to buy a bunch of tools and watching the game at Tripp's.

Today we had lunch at church and I got to work after. I made a mount for the power steering reservoir and finished that up while Tripp worked on modifying the ECU mount.

I got a press in fitting to convert the pump to remote res. It's 10AN fittings and 5/8" pushlok hose for the supply. The return is 3/8 line with a 6AN pushlok fitting.

Tripp took the ECU mount I bought, conformed it to the driver's inner fender, and made a mount for the TAC module on top.

We had to run to the parts store to get hose for the power steering return, so we took the upper radiator hose that didn't fit well and found one from autozone that is much better.


It feels good that the parts pile on the bench is dwindling. The only things left are the fuel lines and exhaust pipes with 02 bungs, which should get done this weekend. There's still a lot of parts on the floor that have to go back on though, and fluids, and of course wiring...
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This morning, after a good breakfast, Tripp and I started by mounting the passenger fender so he could keep working on the harness. I went to work on fuel.

I started by mounting a bulkhead fitting in the tank for the return. This jeep has had a 3" body lift at some point in its past. The filler neck was cut and extended with a piece of tube. When it was lowered back to stock prior to me purchasing it, the tube was left alone. I have since lifted it 1", then lifted the fuel tank. The filler was crusty and crimped almost shut, so ordered a replacement.

Then I opened up the holes from the factory fuel line clips that used push pins to 3/8" and put in nutserts. I used a clamp meant to mount a light on roll cage tubing to mount the fuel filter, and cable clamps for the line.
The GM harness was set up to have its fuse block near the ecu, but we ran out of room over there. Tripp built an extension harness to bring it over to the passenger side with the jeep fuse block, and built a bracket to mount it.

Stopped for the day. The factory Buick air intake looks like it's going to work.


I planned to use the quick connect fuel line adapters in the 3rd picture above. They were in an assortment of fittings I got from somebody on NC4x4. I had one of the 5/16 and 3 or 4 3/8 ones. The 5/16 one I had trouble getting on the rail, but I lubed it and it locked on tight. The first 3/8 one was really loose. I swapped it for another one and it snapped on, but I was still able to pull it off the rail with moderate wiggling and force.

Everything I'm doing fuel related is overkill and I'm not going got skimp here. I just ordered Russell's screw together rail adapters and will swap them out.
Today I got the collector pipes installed with the O2 sensors, worked on the trans shifter cable routing to keep it off the headers, put atf in the tcase, and bolted all the front end body work back together.

This week I'll get a couple clamps to mount the coolant bottle, and I'll order an air filter. Other than that and bolting in driveshafts, tightening suspension parts we loosened, and fluids it's down to the wiring to make it run and drive.

The parts pile is down to driveshafts, battery, arb compressor, bumper, swaybar and armor. I do need to fix the winch while it's off though.