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XJ 5.3 swap (build)

blistovmhz

NAXJA Forum User
Location
Vancouver, BC
Hey all. I've been waffling on an engine upgrade for a few years, but wanted to wait till my 4.0L failed to get me home one day. Well, that day still hasn't come, but my roomies lady folded his civic in half, and with the insurance money he bought himself a foxbody mustang. First ride and I knew it was time to dump a 5.3L into my Jeep. I completely forgot how good it feels to not be the slowest on the road.

So, that said, I picked up a 5.3L long block and 4l60e trans out of an 05 Sierra S1500.

I'm hoping someone can steer me right here anywhere I'm about to waste a bunch of time/money.

The plan:

Drivetrain:
5.3L bolted to 4l60e transmission. Will be using Novak motor mounts and headers (on principal, I didn't want to go with Novak, but knowing the headers fit on the first try is a pretty big selling point. Up here in Canada we don't have a lot of performance shops where I could just walk in and measure headers. Store employees and managers get super offended if you ask any questions about their products.).
The 4l60e trans will be mated up to a hybrid NP231j, using Advance Adapters #50-0435 - http://www.advanceadapters.com/prod...d--to-thejeep-np231-transfer-caseadapter-kit/
This kit comes with a 27spline input shaft, but I talked to them about removing it, and they say they'll give me the kit, minus the input shaft for about $300. The kit comes with a 2 piece, 6 bolt 4l60e to 5 bolt NP231j adapter with a GM 40t reluctor and VSS, and a bunch of other little stuff.
I'll also be using AA's transmission mount #716055 - http://www.advanceadapters.com/products/716055--heavy-duty-transmission-mount/

The case:
NP231j case, NP231j output shaft and SYE, NP241c 6 pinion planetary, and either the NP231c or NP241c input (both are 27 spline).
I'm not sure if the 241c input will fit with AA's adapter, but the 231c they say will fit perfect. I've also got a spare pre-95 NP231j case sitting on my shop floor, and wondering what the difference is pre and post 95? AA says their adapter only fits post 95 j cases, but I'm not sure why and the guy I spoke to didn't know. I'd LIKE to just start swapping the 231/241c internals into my pre-95 j case right now, while I wait for parts to start arriving, but don't wanna waste my time. So, anyone know what the difference is, from the perspective of my hybrid setup? (i'm guessing the cases are physically identical and that for my purposes, it'll bolt right up to the AA adapter).

The rest of the drive train is pretty self explanatory. I'll be ripping out the stock case shifter linkage, flipping the case lever 180 (pointing up) and building a single direct linkage.
The trans shifter I'm still thinking on. I have a floor shifter cable from an 04 sierra s1500. I'll probably end up with an XJ floor shifter and figure out a way to make the cable work.

Cooling:
No idea yet, other than I'm NOT going with any of the direct fit XJ rads. Probably a Griffin 24x19" 2 core, 1", driver input, passenger output, (built in trans cooler) wrapped in one of their shroud/fan packages. The Griffin package with everything included is only around $550, while the Novak/AA rads are $700 naked. Absolutely insane.
The Griffin 24x19" is rated to 400HP, so should be more than sufficient, and should fit on the passenger side. I've already cut out the lower rad support for another project, so it should fit perfect.

Harness:
Picked up a harness, pedal and TAC from an 04 S1500. Going to modify the stock harness. Probably just delete EVAP, AC, and maybe the rear O2's.

Also grabbed a handful of spare sensors, coil packs, injectors, and a y-collector from the 04. Will use the collector to a 3" out. Will run a single cat and single muffler. MAY run a single post-cat O2 just to monitor for cat failure.

Gauge cluster:
No idea yet. May just swap the Jeep oil and coolant temp sensors over to the 5.3, run my J case SYE with Jeep Speedo (and the VSS to the ECU), and do a tach emulator and retain the Jeep cluster. Most likely though, once I've got the thing running, I'll probably just build my own controller (arduino/raspberrypi) to drive an LCD with the GM inputs.
Any insight here would be awesome.

Fuel delivery:
Stock XJ pump with regulator removed. Inline 58psi (adjustable) regulator will be installed. Probably run Nylon lines as recommended by another forum member (ease of installation and low cost). May end up with steel braded. We'll see.
My stock pump may not be tip top, in which case I'm looking for suggestions on a better pump option.

I'll update as I think of stuff and as work gets done. Right now, the 5.3L, 4l60e, NP231c, NP231j, NP241c planetary and input, 04 harness/pedal/TAC, are all sitting on my floor. Block is bolted up to the trans and the tail cone is removed. Don't have anything left to do either until parts show up, or someone can confirm for me that the pre/post 95 j cases are identical (and will have identical input shaft stickout).

Looking forward to input guys.
 
Yep, You're pretty much doing what I'm doing.

The direct TC linkage will be tough because the 5.3/4l60 is shorter than the 4.0/AW4 combo so the TC linkage is 2" behind the opening in the floor.

You can get a stock replacement Walboro 255L pump for pretty cheap. Its cheap insurance.
 
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