Swapping engine out from a KJ 2.4 to a 3.7 (or 4.7 if poss)

Hi,
This will sound like a very odd question to a lot of you, but bear in mind I am not in the US, so thing over her in the UK are different and we get different spec of KJ over here.
My question is: how difficult is it to swap out in KJ Sport manual a petrol 2.4 to a 3.7 ? of possibly to a 4.7 ? keeping the manual 5 speed gearbox or even 6 speed.
You might ask why? Here is the reason:
1) In the UK only the very early KJ 3.7 came in Sport ie 2002 max 2003, almost all are Limited or Extreme Sport editions all AUTO and I don’t like them, prefer sport model. Our Sport models are only missing the leather seats and the coloured bumpers & wheel arches, we have all the other toys like power windows, mirrors, Aircon & EVC, etc.
2) All the KJ petrol 2.4 are manual over here, same as in the US, and come already with 4.11 axel ratio, so if it’s possible to put in the 3.7 you have already re geared to allow for 32’ tyres.
3) The other way of looking at it, am I better off de badging and swapping out coloured bumpers & wheel arches to a sport and re gearing a 3.7 to 4.11 axel of a 2.4? But I would still love to have a manual gearbox instead of an Auto!?
Sadly I missed out on a very rare KJ Sport 3.7 Auto on Ebay ( had head gasket blown )and I have found another one, but they are asking too much for what I want to do.
Any advise is welcomed.

Tks,

Fil.
(PS: I have posted the same question on LOST Jeeps for those how switch between forums ;-) )

You will need...............

-trans for the 3.7,NV3550 or the 6 speed,good luck with keeping either alive behind a 4.7 V8
-new cradle since the 2.4 cradle is different then the 3.7
-new left and right CV axles since they to are different(length wise)
-new front and rear driveshafts
-PCM and all the engine wiring
-all the small things that kill you,hoses,mounts(engine and trans),and all that fun stuff


For the amount of $$$ and time I'd learn to like the auto trans,find a '02 or eraly '03 with the 45RFE which blows the 42RLE out of the water.

Tjkj,
thank you for your answer, I guess that has put things into prospective. I guess my options will have to be keep an eye out for any 3.7 Sport appearing for Sale. Most on sale over here are Limited and I guess, I might have to change the body pannels & bumpers.
I have two question though:
1) How can I tell if a KJ from 2001/2/3 has an 45 RFE and not a 42 RLE?
2) I guess if I wanted to regear, I could simply swap out the diff of a KJ 2.4 to the 3.7 and so get 4.11 ratios in the axels with out problems?! Straight swap?! ( we have a lot of KJ 2.4 petrol around or CRD 2.5 with 4.11 ratios).
Thank you,
Fil.

1. Build sheet or another way is look at the crossmember under the xfer case/******. A 45RFE one is like /----\ but the 42RLE is just |----| kinda.

2. Yep, you can swap the diffs, just make sure you swap the rear gears too.

1. Build sheet or another way is look at the crossmember under the xfer case/******. A 45RFE one is like /----\ but the 42RLE is just |----| kinda.

2. Yep, you can swap the diffs, just make sure you swap the rear gears too.

HoosierJeeper said:

1. Build sheet or another way is look at the crossmember under the xfer case/******. A 45RFE one is like /----\ but the 42RLE is just |----| kinda.

Click to expand...

Hoosier,

What to you mean by this? /----\ or |----|.
Any chance of some photos? are you referning to the Crossmember bar? Most KJ luckly over here odon't have skid plates, so once you look underneath you should be able to read the writing on the transfer case, but an easy visual would be easier to relate to.

Fil.

Shape of the Trans pan is a sure give away.

Come on guys.. it's as simple as that..

Bolts holding the pan :

42RLE = 13 10mm bolts (part #6501474)
45RFE = 15 8mm bolts (part #6101221 or 6503232)

Those 8mm ones are ridiculous, found many cross-threaded right from the plant..