Talk me into/out of a TJ repower with LS

Caver Dave

Caver Dave

Just holdin' it down here in BFV
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Mar 10, 2005
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Hooterville (24171)
My 24 y/o "DD" (driven around town and hauling the dogs from house to shop/back) is nearing chronic.

Ran across a local TJ with a blown motor (4 banger/5spd)... was thinking 4.8L LS/auto repower + 8.8 would give it the umph/reliability and obviously coily springs would ride mo better... 31"-33" max tire?

Is it a level 10 "fawk me for thinking this" job or a level 5 "so easy a caveman can do it"?
 
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Caver Dave said:
My 24 y/o "DD" (driven around town and hauling the dogs from house to shop/back) is nearing chronic.

Ran across a local TJ with a blown motor (4 banger/5spd)... was thinking 4.8L LS/auto repower + 8.8 would give it the umph/reliability and obviously coily springs would ride mo better... 31"-33" max tire?

Is it a level 10 "fawk me for thinking this" job or a level 5 "so easy a caveman can do it"?
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My neighbor did this exact thing about 3 years ago, all by himself, and he had never even owned a jeep before. What are you waiting on?



























Of course he had been a professional fabricator for nearly 30 years, ran his own auto repair shop for 20 years, raced and built drag cars his entire life, and swapped v8's in many things before including jeeps, has 3 lifts, and every tool imaginable. But he had never owned a jeep before. :laughing:
 
@marty79 has done a handful and has figured out a lot of tips and tricks I think
 
I've done 7 now, mostly Gen5, 2 gen3, and a gen 4, coyote swap etc..you can call me probably easier to chat or tonight I can type out details.
 
So to be perfectly honest, the big stuff is easy peasy and it's all been done before. It's the details and small things that take time.

Buy a set of motor mounts (I used Dave's), buy or get someone to cut down a harness, and you can have it in and fired in a weekend. It's the plumbing and wiring and AC and and and that sucks. I have a little over 5k miles on my swap and I still don't have reverse lights, cruise control, and I need to rework some of the engine harness fuse block. But I love it and would do it again.

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Caver Dave said:
I recall seeing some resources on integrating with the factory gauges, etc. but don't remember where... what did you do in that regard? "Integrate" or rip/replace with compatibles?
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I planned to use factory gauges. You need a tach emulator and run both pcms. I don't know if we cut a wire we shouldn't have or fried my jeep ecu, but after spending a day troubleshooting no gauges I pulled everything out and spent $1200 at autometer. I think the simple/cheap/easy way would be some cheapo amazon gauges.

If you're bored and want detail with a parts list...
www.offroadsc.com

LM4 5.3L and 4L60E swap into 2004 LJ

I decided long ago that if anything major happened to the 4.0/42RLE in the LJ that it would not be repaired or replaced with the same. I knew I wanted an aluminum block LS for the weight savings, and I wanted a gen III motor. I've been keeping my eyes open for a good deal to have stashed away...
www.offroadsc.com www.offroadsc.com
 
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Without the experience I'd....1. try and find a complete vehicle, so you will have all of it. 2. Find a place for several friends to come and help out, provide good food, an end of the day good BS session around a fire pit.3. Take a good look at the link above and have all the pieces to make it happen. 4. before tearing into it, measure the auto and see if you'll have room enough for a decent length drive shaft, that seems to be a common issue, esp if you ever try and lift it. And 5. Check on a reman engine, cost vs PIA swap. , Oh and another, outfit it maybe with a Sniper, with it being able to talk to the trans, pretty sure most of all that is plug and play, giving you all the options you need and some you won't
 
I have some Motor mounts already made for a LS in a TJ btw, weld in over factory ones and done...provide 1.25inches of adjustment front to back.
Put the motor forward as far as you can, just enough room to change the belt/tensioner with the fan on if you go with 6L80.
Stock Truck manifolds work beautifully in these TJs...don't listen to what others tell you about not fitting, they work and fit perfect, pass side dumps exactly where you want it and such.
Get the 6an fuel line and adapter for the fuel rail and frame side (only need a 4ft piece)...YOU DON"T NEED TO CHANGE YOUR FUEL PUMP...if your not pushing 400+ with a big cam, run the factory fuel pump and leave it be...trust me. Gen 5s require the most and they run fine on factory pump...5 customers are using them and they haul ass on those Gen5s.
T-case can be 231/241 whatever you choose..I have a guy running a LJ with Tons, 40s, Gen5 tuned to 430hp to crank running np231 with 32spline input and output and holding up fine..added extra little rubber mounts on the rear of the case also...he launches the crap outta that thing with 5.38s and 4:1 First gear 6L80. (btw 32spline input from a chevy case fits into the jeep NP231).
Gen 3 wiring is super easy...only 3 wires and done.
If your running electric fan, don't waste time/money on anything but the Camaro SS fan...you need a PWM controller but those fans are insane.
You can easily have all factory gauges working except tach and speedometer...those 2 must use Dakota Digital module to get them working...(still cheaper than whole new gauges).
You'll be happy enough with a regular LS 4.8/5.3 but if you really want to feel the "worth it", put a Gen 5 5.3 or 6.2 (NOT a Gen 4 6.2 camaro) and you'll be super stupid happy lol.
 
shawn said:
5.9 Dodge swap

Normally I'd say just do a stroker, but since you have a blown up 4 cylinder.... Eh
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I'm curious. Why do you like the 5.9 swap? Is it easier because it doesn't cross brands?

No sure why I am asking. The DMV will revoke my drivers license due to old age before I finish mine and determine it is underpowered.
 
drkelly said:
I'm curious. Why do you like the 5.9 swap? Is it easier because it doesn't cross brands?

No sure why I am asking. The DMV will revoke my drivers license due to old age before I finish mine and determine it is underpowered.
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Integration with the factory electronics is much easier. For an LS, you have to run both computers to get everything to function correctly. Also why Hemi in JK is much more common vs LS.
 
drkelly said:
I'm curious. Why do you like the 5.9 swap? Is it easier because it doesn't cross brands?

No sure why I am asking. The DMV will revoke my drivers license due to old age before I finish mine and determine it is underpowered.
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I had everything on hand to do that exact swap back in 2011/12 but our move to Raleigh forced me to sell off the swap parts.
Had a 5.9 from a ZJ, AX15 with a Dodge 3.9 bellhousing, PCM from a Ram w/o SKIM and the harness was a Hotwire Automotive item. That was the only thing I hadn't done yet (send off old one along with PCM). It was going to be a very simple swap and all the OEM electronics, gauges, etc would play nice with each other.
Things like PS hoses and AC lines were all OEM items as was the fuel system. Aside from the frame side motor mounts, would have looked OEM with the ZJ air intake adapted to the TJ air box.
One day I'll do the swap.
 
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