[Tweak]

Very unlikely. There is simply no info out there. People put LS's into JK's because there are tons of aftermarket companies out there that provide the parts and the programming.

Also, the 5.9 makes less HP than the 3.6L pentastar. Only 50 or so ftlbs more torque. It would cost thousands to install for no huge gain.

 

[Txrdstr]

That motor and tranny suck. Wouldn't even consider it.

 

[WashingtonWrangler]

Don't pick it up at all if you can help it. Not only will it have less hp, it will weigh a whole hell of a lot more than your 3.8. You'll have to redo your entire front suspension, and a bunch of other work, for a negligible overall gain in torque. Not to mention if something doesn't go right the first time (if you've ever done any sort of engine swap you'll know that's usually the case) no one will be able to help you. An LS would serve you much better, or if you want to be different throw a coyote in. But skip the magnum. As for the rest of the drive train, dodge d60's are tough for jk's. I've seen a lot of the fronts passenger drop, and there's relatively no aftermarket support compared to ford 60's.

 

[HerJeepNotMine]

I have not, but I will follow along if you don't mind.
I actually have the same truck in an '01, 125,000 miles, lol it's been a back up vehicle basically.

Carry on

 

[Gr8apmech]

Even with the Hemi swap I've read that you have to use a Cherokee v-8 pcm to hook up to the stock dash software.
Lots of them out there so I'd stick with the Hemi if it's your first swap. LS is a better motor in my opinion but the Hemi isn't bad either.

 

[MCE Mike]

If you want a gutted, bare bones non emissions JK, the 5.9 and drivetrain would be an "easy" swap, since it's electronics are much simpler and reduced. However, one of the 2 main issues you will run against is the emissions. It will not be emissions legal. If you don't have any sort of inspection to go through, then this might only be an issue if you try to sell the Jeep, most buyers will only want something that is legal.

The other issue will be integrating the dashboard and gauges. The 5.9 is an older style of electronics and signals.

However, if you were committed to an offroad only JK, gutting the OE wiring, using aftermarket gauges or an old TJ cluster, and making it a simplistic and reliable Jeep for 4-wheeling, then it could certainly be done. Probably very easily if you have done an engine swap before. It would be just basic placement, wiring and plumbing.

But with all that said, although receiving a big torque boost down low (but less HP up high), the advantage to running a stock 5.9 mag would be arguable. I run my 3.6 JK off road with a good friend's TJ with a stock EFI 351W we put in a few years ago. My Jeep is heavier and spins taller tires with higher gears, and will walk away from the old school V8. I'm sure the v8 would crawl better if I had an manual like he does, due to the low end torque of the v8, but since you are talking doing an automatic it's a moot point.

Also, the 46RE automatic would need to be rebuilt and upgraded, IMO, to be reliable.

EDIT - there was an Alaska JK in one of the magazine a while back that had it's complicated wiring gutted, and was running a Ram Jet 350. Part of me really liked that build: the advantages of the JK, but with the simplistic power train.

 

[dvn4life1972]

OP said he has a 2007 JK. That's not the Pentastar 3.6L.

X2 on what Mike said...about the emissions.

 

[Tweak]

OP said he has a 2007 JK. That's not the Pentastar 3.6L.

X2 on what Mike said...about the emissions.

I was waiting for someone to bring that up.

It's still an unrealistic idea.

 

[MCE Mike]

OP said he has a 2007 JK. That's not the Pentastar 3.6L.

X2 on what Mike said...about the emissions.

That's right, for some reason I got on a Pentastar thought. Thanks.

 

[MCE Mike]

If you want a gutted, bare bones non emissions JK, the 5.9 and drivetrain would be an "easy" swap, since it's electronics are much simpler and reduced. However, one of the 2 main issues you will run against is the emissions. It will not be emissions legal. If you don't have any sort of inspection to go through, then this might only be an issue if you try to sell the Jeep, most buyers will only want something that is legal.

The other issue will be integrating the dashboard and gauges. The 5.9 is an older style of electronics and signals.

However, if you were committed to an offroad only JK, gutting the OE wiring, using aftermarket gauges or an old TJ cluster, and making it a simplistic and reliable Jeep for 4-wheeling, then it could certainly be done. Probably very easily if you have done an engine swap before. It would be just basic placement, wiring and plumbing.

But with all that said, although receiving a big torque boost down low (but less HP up high), the advantage to running a stock 5.9 mag would be arguable. I run my 3.6 JK off road with a good friend's TJ with a stock EFI 351W we put in a few years ago. My Jeep is heavier and spins taller tires with higher gears, and will walk away from the old school V8. I'm sure the v8 would crawl better if I had an manual like he does, due to the low end torque of the v8, but since you are talking doing an automatic it's a moot point.

Also, the 46RE automatic would need to be rebuilt and upgraded, IMO, to be reliable.

EDIT - there was an Alaska JK in one of the magazine a while back that had it's complicated wiring gutted, and was running a Ram Jet 350. Part of me really liked that build: the advantages of the JK, but with the simplistic power train.

It's too late to edit this post, but I apologize for some reason I was thinking '12 and later JK with the 3.6. The 5.9 Mag would have considerable more power than your 3.8, but again, the wiring, emissions, etc.

It sounds like you're trying to retain the stock electronics in your JK. If so, a Hemi or LS swap will be much easier since there are already kits, but also more $$.

 

[dvn4life1972]

I was waiting for someone to bring that up.

It's still an unrealistic idea.

I agree with you. More trouble than it's probably worth, although that can be subjective.

 

[Tweak]

I agree with you. More trouble than it's probably worth, although that can be subjective.

Yup. There are just so many better options out there. LS motors have almost infinite options for increasing horsepower. 500-600 HP is no big deal. 4BT's are making 440ftlbs of torque easy. Hemi's are expensive but that's another option. All of those options have aftermarket support.