LS engine swap options?

TheKrebsCycle

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Hey guys,

I've been trying to plan out my build and I'm researching engine swaps. I have the 4.0L 5 speed in my '98 with either 3.73 or 4.10 gears (not sure yet, only had it for a few months, gonna check it out when I change all my fluids this week). My thoughts are to buy a junkyard motor and drop it in, and then add upgrades later down the line after I've upgraded my axles (I have a 44 in the rear so I should be fine for a while with a stock LS, provided I drive carefully). I might upgrade my axles at the same time, haven't decided yet.

I was wondering if some of you with experience in this field have any opinions on what size engine I should be primarily looking into for a swap. I've been considering 4.8L, 5.3L, 5.7L, even up to a 6.0L if I can convince myself it'll fit easy enough and won't drain my bank account all at once. I'm planning a junkyard swap so it shouldn't be too crazy expensive, but you never know. Thanks!
 
5.3 all the way. It's affordable, it's easy to find a donor vehicle (which is the route I would go, get the entire vehicle), and it's all the power you need in a short wheelbase TJ.

Your AX-15 will be more than up to the task of handing that engine, and Novak makes all the conversion parts you'll need to bolt it up.

Your stock Dana 30 and Dana 44 are just fine with the V8. You'll want to add chromoly axle shafts and the appropriate gears, but other than that, you DO NOT need bigger axles unless you plan on running larger than 35" tires.
 
All of that is great to hear, especially because I love having a manual, and my buddies who are also LS-swapping have told me "it's too difficult/expensive to get a manual." I've been planning chromoly axle shafts anyways as well as a regear.

I have 35's right now, and might go to 37's eventually after I stretch the wheelbase and get full width 44's or 60's underneath (or even a 9 inch). I've got big plans for her!

Thanks for the reply!
 
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Your buddies were wrong. The AX-15 is the perfect transmission for a V8 swap, it's actually a very good transmission.

If you go to 37s, then you'll want some wider axles (and stronger axles too), but with 35s, a built Dana 30 and Dana 44 combo are more than up to the task.
 
Great! I fell in love with a manual transmission when I bought my Jeep. Had only driven stick a handful of other times in my life, but 4 months later now I'm saying I never want to drive an auto again lol

I'll probably get a rebuild on it when I drop the engine in, gear shifts are becoming less smooth but that's expected on a 175k mile vehicle. I need a clutch soon too. Would you recommend upgrading that as well? I would like to overbuild it so it's up to the task of high horsepower.
 
Stick with the 5.3 and you will be fine with that trans and a decent clutch . The 6.0 has a substantially taller intake and you will need to mod the hood . I did the 6.0 in my CJ8 because that’s what I got the deal on. The 5.3 will be less money and an easier fit. Don’t forget to redo the driveshafts with quality ujoints ! I found out the hard way ...
 
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Great! I fell in love with a manual transmission when I bought my Jeep. Had only driven stick a handful of other times in my life, but 4 months later now I'm saying I never want to drive an auto again lol

I'll probably get a rebuild on it when I drop the engine in, gear shifts are becoming less smooth but that's expected on a 175k mile vehicle. I need a clutch soon too. Would you recommend upgrading that as well? I would like to overbuild it so it's up to the task of high horsepower.

The stock clutch will be just fine with a 5.3, but I would have the transmission rebuilt. At close to 200k, it's getting time for a rebuild.

I believe @Clint Rivera has a 5.3 in his as well.
 
Stick with the 5.3 and you will be fine with that trans and a decent clutch . The 6.0 has a substantially taller intake and you will need to mod the hood . I did the 6.0 in my CJ8 because that’s what I got the deal on. The 5.3 will be less money and an easier fit. Don’t forget to redo the driveshafts with quality ujoints ! I found out the hard way ...


Okay, don't spread misinformation. The truck manifold, whether it's a 4.8, 5.3, or 6.0 are the same tall style manifold.
 
OP, the 4.8, 5.3, and 6.0 are all small blocks and are the same external dimension. Same with the LS1 5.7. I'd say pick one that's lowest mileage for the best price. They all rip in a TJ.

I have an LQ4 (6.0), and have helped with a few 5.3 swaps. I'd also run a 4.8 no problem, they can all be pumped up very easily.
 
Thanks for all the information everybody. So really it sounds like I need to just play it by ear and see what I can find. All options sound like they'll work tremendously.

Do any of them off-the-bat offer any advantages that are worth noting? Any disadvantages I should keep my eye out for when looking?
 
The bigger they are, and more you spend, the more power. :D

The basic truck 5.3 is very plentiful, cheap, and excellent power.
 
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Very interested in which route you go. Which harness, flywheel, etc.
Im currently gathering parts and knowledge before I take the leap.
Side note:
I have read that you want to find a 5.3 with 862 heads.
 
Hey guys,
Digging up an old thread. I'm considering an LS swap in the TJ, specifically a 4.8 or 5.3, and am curious about cams for low / mid range torque.
I've talked to a couple guys who have done the swap and having all the power at 4400-5500 RPMs is a little less than ideal. I'm thinking to bump that down 500-800 might be a little better for a crawler.
The 4.0 turns about 2800 RPMs at 70 mph. One of the guys I was talking to said his 4.8 turns about 2200 RPMs at 70. Maybe there is some wiggle room in there.