Swapping a Vortec 6.0LQ4 in my 98

[cdsurf]

Solid info guys. Thanks. I MAY have a hookup on a 4L65E from a friend. If I can get it I'd just to get a decent shop to rebuild it.



The axles and my emissions setup are the major unknowns left to plan out. Living in a state that's strict about that adds so much headache because now I might have to modify my gas tank (beyond just a pump upgrade) to have a tank pressure sensor, I need the downstream O2's and to put the advanced EVAP equipment in there.



For axles I'm damn near clueless as I'm just learning about them. I'd prefer something that doesn't cost $3k just for the rear, but if I'm forced to get one I will. There will be no welding until the build is done and I take it to my buddy to add frame stiffeners. Almost all the aftermarket axles I see require welding.

[JohnX]

An 8.8 is pretty strong, unlikely you'll break it unless you bind it up somehow. I'd just stay with that.

The front is more concerning if you plan to wheel it harder than a fire road. The Rubicon 44 is probably the easiest upgrade, but barely better than the 30.

I may have missed it, but what size tires are expected?

[cdsurf]

Originally Posted by JohnX

An 8.8 is pretty strong, unlikely you'll break it unless you bind it up somehow. I'd just stay with that.

The front is more concerning if you plan to wheel it harder than a fire road. The Rubicon 44 is probably the easiest upgrade, but barely better than the 30.

I may have missed it, but what size tires are expected?

31 to 33, no off roading, just looking for a punchy small SUV which in the warm months will move trackday stuff. I want the extra go because it'll be my only vehicle for a while and the 4.0 ain't doing it for me. The only bolt in 8.8 I've seen is on ECGS.



I also need to figure out what ratio I'll need.

Currently I'm thinking :

• Gearing - 4.10
• Tire Size - 31"-33"
• Speed @2K in 4th - ~65MPH-~68

[JohnX]

I think a 33" tire with a stock lq4 and an 8.8 is a very safe bet for basically on road use. If you "really" are not offroading, then even the d30 is fine...but I'd upgrade brakes and axles anyway.

[cdsurf]

Originally Posted by JohnX

I think a 33" tire with a stock lq4 and an 8.8 is a very safe bet for basically on road use. If you "really" are not offroading, then even the d30 is fine...but I'd upgrade brakes and axles anyway.

That's great to know. I'm gonna aim for the 8.8. One from ECGS with disc brakes, 4.10 gearing, and a few other bits comes up to ~$2600 delivered. As for the front I'll have to think about that as well but it might wait until fall. I need this built and ready to go by mid/late may.

[98LimitedLQ4]

Originally Posted by cdsurf

I hear you and I would have gotten a 5th gen T4R or a Tacoma if I had the space. Most trackdays should be 2 people and 2 people worth of stuff, but there are some where 2 more of the homies might want to go. Maybe I'll just set a cut off at 2 and be done with it. The last thing I need is some major accident.




Sidenote: Where's OP? I feel like I hijacked his thread but he isn't on here.

I’m just now getting caught up on the replies, I’m still waiting for the Novak mounts and headers to arrive and in the process of cleaning off the Explorer rear axle. The LQ4 will see plenty of abuse both on and off road and a turbo is in the works after it’s all installed and running. Nothing crazy maybe 8-12 pounds of boost. Looking to get a second block and build it all forged for when I add a window to this 6.0. I was told the 8.8 should hold up to 500+hp so I want to get to around there. So the recommendation is a D44 front?
Still have to figure out if I want to keep the Chevys NP electric t-case or swap in the NP242J. Hopefully the mounts get her this week and I can start the swap. I’m definitely keeping the 4L80E, so a 8lb sledge should massage the tunnel? I found a lead on DVB XJ hoods from some guy in AZ. And just going to rework the factory alt bracket to keep the accessory drive intact.

[98LimitedLQ4]

Originally Posted by VAhasnoWAVES

hasnt posted since his first post.

im wrapping up my 5.3/4L80 swap in my colorado. one thing i wish i had looked into more was the use of the 6L80. i am seeing them more and more in offroad vehicles. gm has had great reliability with this trans in OE applications (not to be confused with the turd 8L80). i would have to look it up in CAD to comment on the width, but i know it is physically shorter than the 4L80, closer to the 4L60 length.

After a couple of days of checking back with no replies I joined a few FB groups so see about some advice, I apologize for the slow response time. The truck I bought was a salvaged truck with the LQ4,4L80e and NP? t-case. Since all 3 work great with 131k miles I would like to just swap in the whole complete assembly if possible.

[98LimitedLQ4]

Originally Posted by cdsurf

That's great to know. I'm gonna aim for the 8.8. One from ECGS with disc brakes, 4.10 gearing, and a few other bits comes up to ~$2600 delivered. As for the front I'll have to think about that as well but it might wait until fall. I need this built and ready to go by mid/late may.

I pick up 2 used Explorer 8.8 rears with 4.10 and LSD disc brakes, off FB marketplace for $250 each, they will need the perches and shock mounts cut off and new ones welded on. This will be the easier of the rear swaps, the wife’s TJ is getting the 2nd one and will need a truss kit put on but they are pretty straightforward, and the new Miller Multimatic 220 will make short work of the welding.

[VAhasnoWAVES]

Originally Posted by cdsurf

That's great to know. I'm gonna aim for the 8.8. One from ECGS with disc brakes, 4.10 gearing, and a few other bits comes up to ~$2600 delivered. As for the front I'll have to think about that as well but it might wait until fall. I need this built and ready to go by mid/late may.

ya... for that price id buy a JY axle and a welder. a really ice one. as said, couple shock mounts and spring perches, its pretty easy to do a rear swap. if you are against that idea just stick with an 8.25 swap if you dont already have one.

on the rare occasion that your using the thing in 4wd, just know you cant bounce it off the rev limiter.

[cdsurf]

Originally Posted by VAhasnoWAVES

ya... for that price id buy a JY axle and a welder. a really ice one. as said, couple shock mounts and spring perches, its pretty easy to do a rear swap. if you are against that idea just stick with an 8.25 swap if you dont already have one.

on the rare occasion that your using the thing in 4wd, just know you cant bounce it off the rev limiter.

I have the 8.25 in there. This is good news because it means that I can get by with the D30 front and 8.25 rear until next spring. Then I can get stupid and upgrade both. . . and maybe change my lift as well.

[rockclimber]

Originally Posted by 98LimitedLQ4

I pick up 2 used Explorer 8.8 rears with 4.10 and LSD disc brakes, off FB marketplace for $250 each, they will need the perches and shock mounts cut off and new ones welded on. This will be the easier of the rear swaps, the wife’s TJ is getting the 2nd one and will need a truss kit put on but they are pretty straightforward, and the new Miller Multimatic 220 will make short work of the welding.

If you haven't thought of this yet, you should do your drivetrain swap and any suspension height mods before you weld the perches so you can set the pinion angle correctly

you can tack them in and snug up the ubolts so you can roll it around while you're working on it.

[98LimitedLQ4]

Originally Posted by rockclimber

If you haven't thought of this yet, you should do your drivetrain swap and any suspension height mods before you weld the perches so you can set the pinion angle correctly

you can tack them in and snug up the ubolts so you can roll it around while you're working on it.

Yeah definitely putting the driveline in prior to the 8.8 going in. I just spoke to the sales team at Novak today, headers are getting shipped tomorrow and the LS swap mounts are next door getting zinc coated so hopefully by next weekend it will all be here and I can start swapping in the motor and trans. After talking with them I may just stick with the 242J for now but he shed some insight if I wanted to go 241c and what wiring I would have to do to the VSS’s. Awesome company to deal with so far.

[clydefrog]

What state are you in? I am in CA and the emissions are a pain with motor swaps but def doable. See my build in my sig.

I have been running a D30 and 8.8 since 2014 with my LS swap and 33"s. I have run most of Moab and the Rubicon without any issues, running tru-tracs. Plan on doing a long arm kit to have better clearance with the exhaust. PM me for any other info, i have over 30k miles on my build and pretty much know all the ins and outs and i am extremely well versed on smog.

Modifying your tank is easy, i did a write up on it with pics (see my build)

[98LimitedLQ4]

Originally Posted by clydefrog

What state are you in? I am in CA and the emissions are a pain with motor swaps but def doable. See my build in my sig.

I have been running a D30 and 8.8 since 2014 with my LS swap and 33"s. I have run most of Moab and the Rubicon without any issues, running tru-tracs. Plan on doing a long arm kit to have better clearance with the exhaust. PM me for any other info, i have over 30k miles on my build and pretty much know all the ins and outs and i am extremely well versed on smog.

Modifying your tank is easy, i did a write up on it with pics (see my build)

I live in Maryland so I will tag this Historic and not have any issues with Emissions or inspections, I would like to delete the EGR and cats and tune out the rear 02 sensors since I don’t need any of that extra stuff. My biggest issue will be tackling the wiring and retaining the factory 98 XJ gauges. I found a trimmed standalone harness from HPI for $319 but don’t know if that is what I need. Novak said I can send in my GM harness and for about $800 they will trim it to work with the LQ4 that I have. Unless it’s a straight plug and play to the Jeep, I’m not convinced that will be money well spent. I appreciate any help or advice you can give. Thanks

[VAhasnoWAVES]

Originally Posted by 98LimitedLQ4

I live in Maryland so I will tag this Historic and not have any issues with Emissions or inspections, I would like to delete the EGR and cats and tune out the rear 02 sensors since I don’t need any of that extra stuff. My biggest issue will be tackling the wiring and retaining the factory 98 XJ gauges. I found a trimmed standalone harness from HPI for $319 but don’t know if that is what I need. Novak said I can send in my GM harness and for about $800 they will trim it to work with the LQ4 that I have. Unless it’s a straight plug and play to the Jeep, I’m not convinced that will be money well spent. I appreciate any help or advice you can give. Thanks

turning off VATs, O2s, EGR, etc is very simple with hp tuners. i picked up a refurbed computer with the basic requirements to run the suite for like... $100. youll spend $300 for the MPVI, $100 in credits, another $250 for the pro package if you so choose. but its fun to play with. and i use it to read DTCs all the time.

ultimately youll want someone to tune it once its in the vehicle. so it may be cheaper in the long run to reach out to a tuner to see if they will turn what you dont want, then once you get it running you bring it to them for a dyno or street tuning session. might also be worthwhile welding in bungs for wide band O2s when you are doing the exhaust so they tuner can utilize them. preferably one for each bank, but one after the Y will also suffice.

its worth considering what ECM you intend to use. the truck stuff is big and bulky, but works. i opted for an E40 ECU and a separate TCM for packaging, but that required loading up a start up tune to get things started.

when it comes to harnesses... if you are going to do it yourself, do what you will. LS1 tech is a good resource for figuring things out. but i would rather pay for a new built harness than a thinned down stock harness. a 20 year old harness is likely dry and brittle. a stand alone harness will leave you with 6 wires or so to hook up gauges after plugging it all in, doesnt sound like what you want.

now... getting the factory gauges to work gets complicated, or expensive. you pick. a lot of guys end up just stuffing aftermarket gauges in the factory bezel and being done with it. the issue is getting the GM can bus to talk to the jeep BCM. there is a company that had their LS powered liberty at LS Fest doing passes down the strip. not that it was much of a street vehicle, but they were there to highlight their module they had created to get the GM PCM to talk to the the BCM of other various OEMs.







good news is your not the first one to LS swap a cherokee. plenty of info out there. do some reading, come up with a plan, start getting your feet wet. but keep in mind specific questions get much better answers than generic, "how do i do it?" questions.