Does someone make a kit to put a GM LS engine in a JK?

jomobco

Now Decanter
:sombrero: I keep saying this and nobody refutes or questions me !!




Why do you want to swap out an already good engine/tranny setup all you gotta do is MOD-

:costumed-smiley-007:wings: JIMBO

1) This post has nothing to do with your question
2) I've got 2 Jeeps which came with 6 cylinder motors which now have V8's and believe me when I say THERE'S NO REPLACEMENT FOR DISPLACEMENT. :smiley_drive:
 

jomobco

Now Decanter
If the 2.71:1 box is compatible then I would have to think the 4:10 box is also compatable since the two are swapable between Jeeps w/o modifications of any kind. Same input and output, length, etc.


JPK

Here was their quote:
"Love the price! Why can't we use the stock 241OR xfer case?"

The 241 OR has a large front planatary to achive the 4:1 ratio with a small spline input gear. The 6l80 has the old Turbo 400 output shaft which is larger and the OR is not available with the large input so a new planatary input gear would be required. This would be very costly to make and demand is not that high.
 

JIMBO

Expedition Leader
:sombrero: I'm afraid you don't understand-


Believe me when I tell you that the difference between a Hemi powered JKU and a 3.8 powered JKU, no matter the gears, is more than you can appreciate, on or off road, unless you've driven one. An LS powered JKU would be the same without the Chrysler/Jeep weaknesses, like programming.

The '12's with the five speed auto and the 3.6 with its additional HP and additional torque over a flat curve will make the JKU a hell of a lot better, imo, but in no way comparable to a Hemi or LS powered JKU. Wait and try one, it ought to be a hell of an improvement over the '11's and previous models.

JPK

I've owned two 426cuin REAL HEMIs, in 1971/1972 (Plymouth) and I have no problem in the realization of POWER, 3.8L vs 426 or LS and LT's which are all high HP engines--

You buy a jeep for off-road playing-not racing or competing, my COMPLETE point is, you can get the 3.8L as "issued", to perform OFF-ROAD with total satisfaction, now if you want a sand/mud dauber--getta sand buggy-

My JKUR will go anywhere-within reason and tow my trailer at the same time and I haven't voided any warranty's or messed with the "world famous" Chrysler On Board Computer sys and I can cruise to the Off-Road spot, in comfort at freeway speeds-with good mileage and comfort--at speed-

It's all in your perspective of comfort and power IN A JEEP, which depnds on how much work/money/time you will invest, with a PROBLEM FREE RETURN !!

:costumed-smiley-007:wings: JIMBO
 

JPK

Explorer
Like I said, and as Jomobco said, if you haven't driven a JKU with the power it ought to have you can't realize what the 3.8 and auto is missing.

If you haven't driven Hemi or otherwise appropriately powered JKU then "your perspective of comfort and power IN A JEEP" is narrowed by your lack of experience with a powerful JKU.

BTW, in 25,000 miles my Hemi powered JKU has needed the oil changed, that's it.

Jomboco, hmmm, I thought the two transfer cases were bolt in swaps for each other. I wil have to look into it since it seems I'm totally wrong on that. If the swap would be limited to the 2.72:1 transfer case maybe a doubler or a another case would be better.

JPK
 

JPK

Explorer
From MoTech's email to me:
"Your looking at $15k for a 5.3/6l80 with all the options-Cruise Control, Tap Shift and heavy duty cooling.

For a 6.2 $18k with all the options, as above but with upgraded drive shafts.

This price will include a NP241C, if you want an Atlas add $2k.

This price is for a low mileage engine, add $2k if you want a new crate engine.

We have not done a 2011 yet and the steering wheel controls are somewhat different. We will be doing a 2011 Sahara from Texas shortly.

Also keep in mind we need a 2011 or newer engine to keep it compliant if that is a concern."

That is attractive pricing... Hmmm...

JPK
 

jomobco

Now Decanter
From MoTech's email to me:
"Your looking at $15k for a 5.3/6l80 with all the options-Cruise Control, Tap Shift and heavy duty cooling.

For a 6.2 $18k with all the options, as above but with upgraded drive shafts.

This price will include a NP241C, if you want an Atlas add $2k.

This price is for a low mileage engine, add $2k if you want a new crate engine.

We have not done a 2011 yet and the steering wheel controls are somewhat different. We will be doing a 2011 Sahara from Texas shortly.

Also keep in mind we need a 2011 or newer engine to keep it compliant if that is a concern."

That is attractive pricing... Hmmm...

JPK

I'd do an atlas. I've got one in my YJ and it's the bomb (proof). Pricing wasn't quite as good as I thought. Here's my thinking:
New BOR 2011 5.7 VVT with 400/400 $21,500. New everything plus 3/36k warranty on parts.

6.2 has 392/417 approximately.
$18k for above plus you won't have the option to do Rubicon axles or if you wan't the 44's then you need to put in a new xfer case in the rubi - $2100. If you do a JKU X or such you can save a bunch but why do the HP without the goodies like the axles/lockers, 4:1, etc. unless you already have a built JK then it would save you.
Add another $2k for new parts. Total $22,100.00 but you get an Atlas.

With the 5.7 you'll have a single ECM and a single CEL. With the 6.2 you'll have 2 ECM's and 2 CEL's. With the 5.7 you can go into a dealer and babysit them through a repair. With 2 ECM's I'd be more nervous. Is it a chevy ECM problem or a chrysler ECM problem?

If you're thinking you'll go chevy to add HP parts then why not just do the 6.4VVT (other than the 5k upcharge :Wow1: ) It has more than you'll ever want and more than any "real" hemi ever put out from the factory :shakin: But then you have to get into bigger than a rubicon 44 axles, etc. but hey, going fast costs $'s.

I love chevy's in Jeeps but to me the 5.7/6.1/6.4 make more sense unless you're talking the 5.3 basic build. I think the 5.7 VVT is what should have come from the factory - damn them.

Thanks for the info and looking into this.
 

JPK

Explorer
I already have the Hemi in my Unlimited Rubicon, as mentioned previously. I went AEV because of the lack of troublesome reports and mine has been 100% trouble free.

There is no shortage of power, but from time to time the weak Chrysler programming will have you thinking, "why the hell did (or didn't) the transmission shift up (or down)?" Its rare but it happens when accelerating on the highway. And that is with AEV's improved shifting already set up (but I might try the tow setting to see if AEV's Procal can improve shifting some more.)

To me, this LS set up is the perfect way to go with an X bought cheap - and maybe with the 0% financing Jeep is offering on the '11's, or maybe a well kept mall crawler from an earlier year. Use the savings and the free money to instal the 5.3 and go with a set of Dynatrac ProRock's, the .5" thickness HD 44 up front and the 60 (maybe the full float?) in the rear. Here's my math - 5.3+6l80 = $15k, Atlas = $2k. Thats $17k. Maybe another $6k for ready to bolt in axles with good shafts, ball joints, u-joints, thick, strong, HD housings, HD forged C's...

Then set the Jeep up with AEV's suspension and bumpers/tire carrier, armor and River Raider's aluminum skids with the ultra high density plastic stuff. Close to perfect... Another $3k gets you the 6.2, but that is just gravy, more than req'd to transform the JKU.

Actually, its a shame Chrysler doesn't offer a good smaller Hemi - not that I'm complaining about the power of the 5.7, but it really is more than enough.

Two other notes.
One: I get between 15 and 16mpg on the highway even with a small roof rack, and that's about as good as any similarly equipped 3.8 JKU riding on 37's, armored, loaded... Around town milage drops to an average of 12.8mpg, but that is no fault of the 5.7VVT, it just that there are more opportunities to run it. BTW, I am running oem Rubicon axles and oem DS's without any issues. I try to be smooth, the abundant torque makes that easier.

Two: I saw Richard Petty (I think) talking about the new Hemi Challenger on Speed TV the other day, he was saying that the new Hemis all have more HP and especially torque than the 426's he used to win Daytona.

JPK
 

jomobco

Now Decanter
I've had issues with my 07 Cummins 2500 6 speed auto hunting for gears but not my '11 JKU 5.7 VVT Burnsville Offroad build. I believe but not certain that it's an updated ECM/programming in '11 which might help with increased efficiency but don't quote me. I actually went by a dealer today who couldn't tell me if the 2011's could be hooked to the starscan or if there was a new tool as I'd been told. Shocker.

Chrysler certainly made improvements on their programming that's for sure however two different trannies and platforms probably contribute as well.

This is the beauty of Jeeps - If I were to do this as inexpensively as possible for me I'd find a 2007 JKU Rubicon with a ton of miles (lowest priced Rubi) and use the Rubi axles and lockers and still do the 6.2 with the low mileage used motor/tranny option and then do an atlas xfer case. IMO with the 5.3 the 60's are overkill and added slowness (weight). At least in the front for sure. Some chromoly and bracing as I have now with my 400/400 5.7 VVT and I think I would be fine. The 5.3 is only pushing 320/340 which is close to what I'm running in my 5.7 Chevy powered YJ and with armor, 60/44 R/F axles, steel Tuffy boxes, etc. and it's about as slow as I want to go for that kind of investment. Add a 4 door JKU and I think the motor might be a tad small for what I want. I tend to tow trailers over long distances with my rigs as opposed to serious rock crawling.

As far as a small hemi I'd rather have a 3.0 diesel in the JK :wings: which I hope we just might get in a year or three. Torque baby torque!

To each their own eh? :ylsmoke:
 

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