XJ - 5.0L swap.

Hey all.
My 98 XJ has taken some abuse. The uniframe is starting to fail at the rear due to some poor engineering decisions, the 4.0L is starting to feel a bit soggy, and the HVAC is destroyed.
I figure I should play it safe and just start a new build. My 98 is built up pretty well, but aside from some armour, everything can be swapped over. Found a real sweet 88 limited for cheap and thus the project begins.

The plan is to start by reinforcing the entire uni-frame rail before I destroy it, get a v8 running, and then worry about the rest of the drive line. The 88 comes with a 3" lift, so I'd just swap out my built d44/d-turdy and suspension to the 88, and then sell the 98 with the 3" lift and axles from the 88.

That said, I haven't decided on a powerplant, but my roomie finally got rid of his ricer (his GF smashed his pretty civic) and he picked up medium built Foxbody Cobra. I heard him pull into the driveway and was sold on the engine. Took it for a test drive in the driveway and was sold on swapping in a 5.0L immediately.

But, I can't find a single complete write up on the 5.0L swap. Lots of guys talking about it, lots of guys saying it's real easy, but NO ONE actually says what's involved.
Anyone know of a complete write up anywhere?

Current consideration:
* Have a line on a 1990 5.0L HO (medium built, cammed, cobra intake, etc).
* I like the AX15, but I'm not at all married to it, and mine (in the 98) is on it's way out anyway. I can always find an AX15 for cheap, but are there better options? I know you can put several ford options under the XJ, but at around 300hp, is there any point swapping the AX15? Finding bellhousing adapters for the AX15 > 5.0L is easy enough (though sorta expensive).
* Fuel delivery - I'm guessing I'd be ripping out the XJ fuel pump (in tank) and just bolting on an aftermarket external Ford pump/filter. I'd prefer the pump to be external to the tank anyway. IIRC, the 5.0L requires 50-60psi so I'm assuming I'd need to run new fuel lines.
* Motor mounts - I'm sure I can fab something up pretty easily.
* Exhaust headers - I've heard that clearance isn't as big an issue with the 5.0L compared to other V8 options. A standardish set of block huggers perhaps?
* Exhaust - Dual or just run a collector and a 3" pipe?
* Cooling - I've heard the stock rad and fans should keep the 5.0L cool, but I'd probably throw in a new 3 core, dual electric fan like the one in the foxbody.
* Dash - No idea here. Completely at a loss. Haven't heard anything about it anywhere.

Thoughts?

Step 1: Talk to Novak.

Novak says they have no info on the swap. The guy I talked to said they've heard of a few guys doing it, but don't have any info other than they don't have headers that will fit (but I've found a few guys who've found some that work), and that I'd need the bellhousing adapter and pilot bearing (which I already knew).

The thing is, I'd love to get a hold of a GenIII LS motor, but I've never seen one for anywhere under $5000 in my area, and I just can't justify that kind of money on a motor I know nothing about and have experience with. If I knew someone local who could help pick out a motor, I'd probably go LS. As it stands though, a freshly rebuilt 5.0L HO can be picked up for $500 any day of the week, and will make the same power as a stock LS1. Yes, an LS can make horrendously MORE power than the 5.0L ever will, but I really don't think I deserve more than 350 ponies in an XJ.

There was one guy who was doing an excellent write up on the swap, but got half way through and apparently had to sell the whole lot to fund a company he was starting. He sounded like he knew what he was doing, and he was confident it was going to work just fine, but just didn't document any of the stuff I need to know

blistovmhz said:

Novak says they have no info on the swap. The guy I talked to said they've heard of a few guys doing it, but don't have any info other than they don't have headers that will fit (but I've found a few guys who've found some that work), and that I'd need the bellhousing adapter and pilot bearing (which I already knew).

The thing is, I'd love to get a hold of a GenIII LS motor, but I've never seen one for anywhere under $5000 in my area, and I just can't justify that kind of money on a motor I know nothing about and have experience with. If I knew someone local who could help pick out a motor, I'd probably go LS. As it stands though, a freshly rebuilt 5.0L HO can be picked up for $500 any day of the week, and will make the same power as a stock LS1. Yes, an LS can make horrendously MORE power than the 5.0L ever will, but I really don't think I deserve more than 350 ponies in an XJ.

There was one guy who was doing an excellent write up on the swap, but got half way through and apparently had to sell the whole lot to fund a company he was starting. He sounded like he knew what he was doing, and he was confident it was going to work just fine, but just didn't document any of the stuff I need to know

Click to expand...

You could go with an iron block variant of the ls. my local junkyard sells complete 5.3s with 100,000 miles or less for $700!

They're just too insanely rare here. I've never seen one in a junk yard, and never seen one go for less than $2500 here.
Not interested in other powerplant options at this point unless someone wants to sell me a GenIII LS, complete, for under a grand, delivered to BC . The 5.0's are just so plentiful and cheap, and I hear all over that they're easily as simple to swap as an LS. Just for some reason, I can't find a complete write up.

That said, the one other consideration I forgot to mention was Mustang vs Exploder 5.0L. I hear some guys swear that the 97-90 stang (cobra) is by far the easiest option, also producing the most power, but heaps of guys swear by an Exploder with a few cobra parts (apparently easier to swap due to harness and OBDii availability).
I'm sure SOMEONE who's done the swap will eventually chime in

The only cobra fox body was produced in 93. The push rod cobra motors were in the 93 & 94-95 cobras. In 96 the mustang went with a modular motor. 96-97 explorers still had the push rod 5.0 though. Came with the Gt40p heads and the truck intake. They don't make as much power as the cobra motors.

RoyalXJ said:

The only cobra fox body was produced in 93. The push rod cobra motors were in the 93 & 94-95 cobras. In 96 the mustang went with a modular motor. 96-97 explorers still had the push rod 5.0 though. Came with the Gt40p heads and the truck intake. They don't make as much power as the cobra motors.

Click to expand...

That's what I've heard, but then there's this guy http://jeepspace.jeepforum.com/472cid
who apparently went with a 2000 exploder 5.0, GT40p head and GT40 upper/lower and e303 cam. Read through some of his posts talking about it, and it sounds like it gets the job done.
WTF is a 2000 5.0L though?

My real question with the 5.0 though, is what's the best way to mate it to the dash or either an 88 or 98 XJ? I figured with the 2000 5.0L, you've got OBDii at the very least, in which case I could just build a new dash and run it on OBDii .
I havne't really seen anyone discussing their dash setups yet.

As i'm still in the planning phase, I've got time to source the best possible 5.0L for my project.

Trying to get my account on JF back so I can track down 472cid to discuss his swap.

Im pretty sure Explorers were made all the way up until 2001 with the push rod 5.0. From 96+ explorers were obd2 so a harness swap is all that is needed. There are companies that can rework harnesses for any build.

RoyalXJ said:

Im pretty sure Explorers were made all the way up until 2001 with the push rod 5.0. From 96+ explorers were obd2 so a harness swap is all that is needed. There are companies that can rework harnesses for any build.

Click to expand...

That's where I'm getting confused. Why do we need to swap the harness in that case (and to what)?

Use the explorer harness because it is plug and play for the 302s sensors. You will need to use the explorers computer to make the engine run.

RoyalXJ said:

Use the explorer harness because it is plug and play for the 302s sensors. You will need to use the explorers computer to make the engine run.

Click to expand...

That was the plan. If I went with a 93 cobra 5.0L, I'd be using the harness that comes with it. Same goes with the exploder. I'd assume I'd just run whatever harness was supposed to come with that motor.
I hear lots of talk about it though and not really sure why guys are swapping harnesses?

You cant find a gen III iron variant for under $2500, but you can find a cheap 5.0L? That doesnt make any sense. Chevy trucks have got to be the most common V8 vehicle in Canada.

Hoooper said:

You cant find a gen III iron variant for under $2500, but you can find a cheap 5.0L? That doesnt make any sense. Chevy trucks have got to be the most common V8 vehicle in Canada.

Click to expand...

Sorry, can't find an LS, which from what I heard, is pretty much necessary to fit the accessory package under the XJ's hood. From everything I've read, an LS is an easier swap than the 5.0, but 5x more expensive for the same output. An LT or something would be the same price as a 5.0L, but every build I've seen in person has had issues with packaging, that ultimately ended up costing way more than the 5.0 swap.

Again, I'm not married to doing a 302, but I've just not seen any GenIII's other than the LS that went smoothly for anywhere near what it costs for the 302. That said, i've never swapped a motor into an XJ, so I'm just going on what i've read online.
Thus, why I bring the question here. I've seen a few really nice SBF swaps into XJ's ( just never seen a complete write up ), while all the SBC's I've seen in person, have left very little room to work under the hood, usually required mounting the block lower than I'd like for pan clearance, or popped way out the top of the hood.

I'd love to have the whole conversation with someone who's done a clean SBC swap, as well as someone who's done a clean SBF swap.

The truck LSx would need the LS or car intake some brackets and accessories. So, that is not a big deal.
Have you seen Jeremy B 's LSx swap thread? He did an AMAZINGLY clean job.
Frank Z, John D, and Hoooper have done the swap as well.
And, as you know, Novak has lots of info and parts if you cannot source them local.

blistovmhz said:

I'd love to get a hold of a GenIII LS motor, but I've never seen one for anywhere under $5000 in my area, and I just can't justify that kind of money on a motor I know nothing about and have experience with. If I knew someone local who could help pick out a motor, I'd probably go LS. As it stands though, a freshly rebuilt 5.0L HO can be picked up for $500 any day of the week, and will make the same power as a stock LS1. Yes, an LS can make horrendously MORE power than the 5.0L ever will, but I really don't think I deserve more than 350 ponies in an XJ.

Click to expand...

I am confused at your liberal use of 5.0l and of LS engines.

Gen III LS engines include the iron truck 4.8l and 5.3l but also the aluminium 5.7, 6.0, and 6.3 Engines.
What one are you looking for? A 5.7l LS1 with transmission can be had for $3000 easy, even with shipping.

A 5.0L is only offered in the fox body years that you are talking about, but mostly you are talking about the 4.6l it seems. The fox body 5.0 NEVER had 350hp, and a freshly built one with 350hp is going to be much more than 500 bucks. The 4.6l is a dog, again only hitting 350hp in variations that would make it far more than the LS1.
There is a reason that LS1 swaps into fox bodies are a nice bolt in kit.



I admire the drive to get a 5.0 into an XJ, and the fox bodies do sound great.
But for the cost and work a turbo on a fresh built 4.0 will be the same price and far easier.

For the exhaust, part of what made that sound you fell in love with is that it probably had long tubes, an H pipe and chambered mufflers, flowmaster 40 is the go to. You are going to have a hard time stuffing that all under there without hanging way down. And will need custom long tubes.

For the dash, I would just get some nice stand alone gauges and cut holes in a sheet of carbon fiber or fiberglass to fit in the factory space.

You'll need a new rad for sure, the old 5.0 stay cool pretty easy when moving, but with the limited air while on a trail it might struggle.



What is your goal for your XJ? rocks? mud? overland? pre runner?

xriide said:

I am confused at your liberal use of 5.0l and of LS engines.

Gen III LS engines include the iron truck 4.8l and 5.3l but also the aluminium 5.7, 6.0, and 6.3 Engines.
What one are you looking for? A 5.7l LS1 with transmission can be had for $3000 easy, even with shipping.

A 5.0L is only offered in the fox body years that you are talking about, but mostly you are talking about the 4.6l it seems. The fox body 5.0 NEVER had 350hp, and a freshly built one with 350hp is going to be much more than 500 bucks. The 4.6l is a dog, again only hitting 350hp in variations that would make it far more than the LS1.
There is a reason that LS1 swaps into fox bodies are a nice bolt in kit.



I admire the drive to get a 5.0 into an XJ, and the fox bodies do sound great.
But for the cost and work a turbo on a fresh built 4.0 will be the same price and far easier.

For the exhaust, part of what made that sound you fell in love with is that it probably had long tubes, an H pipe and chambered mufflers, flowmaster 40 is the go to. You are going to have a hard time stuffing that all under there without hanging way down. And will need custom long tubes.

For the dash, I would just get some nice stand alone gauges and cut holes in a sheet of carbon fiber or fiberglass to fit in the factory space.

You'll need a new rad for sure, the old 5.0 stay cool pretty easy when moving, but with the limited air while on a trail it might struggle.



What is your goal for your XJ? rocks? mud? overland? pre runner?

Click to expand...

$3000 for just the motor, and another $2000-$4000 for the swap is just way outside of what I'm comfortable spending on a beater. I understand some guys want a pretty rig, but I absolutely don't care as long as it gets me where I wanna be.

The 5.0L was used right up to 2001 in the exploders, but with the super sweet GT40P heads, Cobra intake, etc. Essentially came with all the good stuff you'd normally put on a moderately built 302, but with a tamer cam geared towards low end torque. An e303 will wake it right up, though you'd lose a small amount of low end torque, while gaining an extra 2000-3000 RPM and 50HP (You'd also have to upgrade the valve springs in the GT40P). Either way, I can pick up a low mileage 302 from an 01 exploder for $180 from the wrecker any day of the week. I figure I could pick one up this weekend, and if it's toast, I'll just go get another one, etc, until I have all the motor I need .
I've seen guys swap explorer 302's, do the cam and springs, and dyno 280rwhp, which for me is more than sufficient. If I can smoke my 35's on dry pavement, I've already got more power than I deserve.

As for building up a 4.0L, I waffled on it for 2 years before saying no. The turbo route is pretty simple, but as you pointed out, it really requires a fresh rebuild, and at the end of the day it's not giving me any low end torque. The SBC route STARTS at $4000 before I even consider getting it into the Jeep. Correct me if I'm missing anything here. This'll be my first swap.

Ultimately all I want is around 250-280rwhp, in a package that won't get me pulled over for a VI. The 302 just keeps coming back to me as the best option for my purposes.

Building my own dash is probably the best route. I'd be running it all on an arduino or raspberrypi or some other small singleboard, connected to a 7x14"ish LCD. Was just wondering if anyone had ever got the 302 (explorer) to run the stock Jeep cluster.
I've no idea what RAD is in my buddies Foxbody, but I measured it out and I think I can make it fit pretty well into the XJ, so I've been trying to source one out.
x2 on the flowmaster 40. Bang on. Is what I've got in my XJ now.

My Jeep mostly plays in the mud/trails, rocks occasionally, and is also my DD.

I'm not sure where you are getting your engine prices. But I can't even find a junk yard that has less than a 200 dollar core charge on a 302, found several complete 302 for the 1500 range, more like 2500 with harness and computer and accessories though. Right up in the ls1 range but half the power.
A stock 302 hardly has anything on a HO 4.0.

And you want to cam it to get a 302 (stock with 215hp in an exploder) into the 280-305 hp at the crank, so you are 500 into parts in the engine, plus another couple hundred in gaskets. On the cheap. programing the computer is another couple hundred. You will be into the engine for 1000 before you get it off the engine stand, not including whatever you pay for the engine. Custom made engine mounts, maybe headers depending on how they fit.

Looks like the LS1 is 200$ motor mounts and 350$ headers to get into an XJ, then lots of time. And I am sure little odds and ends.

Quick google seems to lead me to think that 5k for an engine conversion is on the cheap side once all said and done. But I have no idea. I have helped put LS1 in a fox body and in a miata. Both have full kits to bolt in install, and was still a pain. And both had 1000 in parts that weren't expected.

Being your daily driver I sure hope you have something else too. I'd say a conservative estimate would be 70 man hours to get the old out and the new in. Without any issues.

I can find 4.6 stroked 4.0 crate engines that put out 270hp with warranty for 3500 bucks. Change it out in a weekend easy. Or build the same for 2500 or so from your current engine.

But I do love build threads, and would love to watch the build go down.

xriide said:

I'm not sure where you are getting your engine prices. But I can't even find a junk yard that has less than a 200 dollar core charge on a 302, found several complete 302 for the 1500 range, more like 2500 with harness and computer and accessories though. Right up in the ls1 range but half the power.
A stock 302 hardly has anything on a HO 4.0.

And you want to cam it to get a 302 (stock with 215hp in an exploder) into the 280-305 hp at the crank, so you are 500 into parts in the engine, plus another couple hundred in gaskets. On the cheap. programing the computer is another couple hundred. You will be into the engine for 1000 before you get it off the engine stand, not including whatever you pay for the engine. Custom made engine mounts, maybe headers depending on how they fit.

Looks like the LS1 is 200$ motor mounts and 350$ headers to get into an XJ, then lots of time. And I am sure little odds and ends.

Quick google seems to lead me to think that 5k for an engine conversion is on the cheap side once all said and done. But I have no idea. I have helped put LS1 in a fox body and in a miata. Both have full kits to bolt in install, and was still a pain. And both had 1000 in parts that weren't expected.

Being your daily driver I sure hope you have something else too. I'd say a conservative estimate would be 70 man hours to get the old out and the new in. Without any issues.

I can find 4.6 stroked 4.0 crate engines that put out 270hp with warranty for 3500 bucks. Change it out in a weekend easy. Or build the same for 2500 or so from your current engine.

But I do love build threads, and would love to watch the build go down.

Click to expand...

Pick-n-pull has complete motor with accessories and harness for $200. Some counter guys will try to charge you extra for the accessories, but I just talk to a manager and they always throw it all in.

As I said, I'm still not married to the SBF. I did a tonne more reading on SBC swaps the past few days, and they really do seem a whole lot easier, and I've found a couple LS1/2 intakes for around $200, so I may be looking into a 5.3L vortec 5300 or something similar.

Strokers just scare me. If I had a good 4.0L to work with, I'd be stroking it, but I don't trust anyone else's work. Seen too many strokers asploded on the trail, and fuel economy discussion ranges from 23mpg to 7mpg pretty consistently, so I don't know who to believe. SBC and SBF swaps (in the 5L range) I consistently hear between 17 and 22mpg if you're easy on the skinny.


That said, if I was to go the SBC route, I think my best option would be something like an LM7 right? I've got a few questions I just haven't found answers that i'm confident with:
1. From what I understand, the lower profile LS intake can be bolted on, but there are some issues with bracketry. Who knows what needs to be done to get the LS intake installed, and will it negatively impact performance/economy?
2. Is there any way to get an AC pump mated to the LM, and still under the hood? (OBA pump)
3. Fuel delivery... I'm not sure which Jeep I'd be doing the swap in. Either a 98 or an 88. What fuel delivery options do I have for either? Can the 98 in tank pump be modified to push the regulated 60psi, or does it make more sense to just modify the pump for no pressure regulation, and regulate at the rail and install a return line? Or should I do like FrankZ and just drop in a chevy pump into the XJ tank?
4. FrankZ talked about putting the chevy cluster into the dash but I don't think it ever got finished. Anyone know more on this?
6. 4L65E or AX15? I prefer manual, but that's probably just because I'm used to having a wimpy motor. I've never driven an auto that was mated to a power plant making more than 150hp .
7. I've heard the water pump needs to be spaced out.... is that only with the LS intake?
6. What 5.3L's are going to be the easiest swap?

blistovmhz said:

Pick-n-pull has complete motor with accessories and harness for $200. Some counter guys will try to charge you extra for the accessories, but I just talk to a manager and they always throw it all in.

As I said, I'm still not married to the SBF. I did a tonne more reading on SBC swaps the past few days, and they really do seem a whole lot easier, and I've found a couple LS1/2 intakes for around $200, so I may be looking into a 5.3L vortec 5300 or something similar.

Strokers just scare me. If I had a good 4.0L to work with, I'd be stroking it, but I don't trust anyone else's work. Seen too many strokers asploded on the trail, and fuel economy discussion ranges from 23mpg to 7mpg pretty consistently, so I don't know who to believe. SBC and SBF swaps (in the 5L range) I consistently hear between 17 and 22mpg if you're easy on the skinny.


That said, if I was to go the SBC route, I think my best option would be something like an LM7 right? I've got a few questions I just haven't found answers that i'm confident with:
1. From what I understand, the lower profile LS intake can be bolted on, but there are some issues with bracketry. Who knows what needs to be done to get the LS intake installed, and will it negatively impact performance/economy?
2. Is there any way to get an AC pump mated to the LM, and still under the hood? (OBA pump)
3. Fuel delivery... I'm not sure which Jeep I'd be doing the swap in. Either a 98 or an 88. What fuel delivery options do I have for either? Can the 98 in tank pump be modified to push the regulated 60psi, or does it make more sense to just modify the pump for no pressure regulation, and regulate at the rail and install a return line? Or should I do like FrankZ and just drop in a chevy pump into the XJ tank?
4. FrankZ talked about putting the chevy cluster into the dash but I don't think it ever got finished. Anyone know more on this?
6. 4L65E or AX15? I prefer manual, but that's probably just because I'm used to having a wimpy motor. I've never driven an auto that was mated to a power plant making more than 150hp .
7. I've heard the water pump needs to be spaced out.... is that only with the LS intake?
6. What 5.3L's are going to be the easiest swap?

Click to expand...

Your pick and pull places are much better then mine out here. I don't think I have seen a fox body 5.0 in one for 15 years. And any running or looks like it might be running engine is a 300 dollar core charge plus at least 1000 bucks. But more often then not they have all the engines worth buying pulled on a pallet already and for sale at 2000+.


The LM7 is a nice engine, and should be plentiful. And the LS1/LS6 intake is the one that will fit better as they are all Gen III, the LS2 is Gen IV, although I think it still fits but then you have to put the knock sensors somewhere else?


Strokers, If your block isn't cracked then the rest doesn't matter as it is a fresh build. I've only seen the far to budget conscience strokers explode. Pick good parts and you'll be fine. And the crate ones with warranty I have only heard great things about.
But up to you.


1. The LS intake will positively affect performance, it is the intake for the sports cars.

2. Might need a cowl hood anyways, but I'm not sure.

3. I would pull the pump and replace with the GM, it will be the easiest solution.

4. Not sure, seems like a lot of work since the XJ cluster is tiny. I would just get some Autometer (or whoever) gauges and mount them to a blank in the dash. Like this http://snsclassics.com/images/dolphin/6blk_red.jpg

5. You skipped 5.

6. I would go 4L65E, But for offroad an auto makes for a much more pleasant ride. Nothing like trying to be delicate on a hill while off camber with a standard.

7. I'm not sure, seems odd though.

6. (your second 6), I would say whatever one has the most aftermarket support in general, and whatever one has the cheapest mounts?



Hope that helps.

xriide said:

Your pick and pull places are much better then mine out here. I don't think I have seen a fox body 5.0 in one for 15 years. And any running or looks like it might be running engine is a 300 dollar core charge plus at least 1000 bucks. But more often then not they have all the engines worth buying pulled on a pallet already and for sale at 2000+.


The LM7 is a nice engine, and should be plentiful. And the LS1/LS6 intake is the one that will fit better as they are all Gen III, the LS2 is Gen IV, although I think it still fits but then you have to put the knock sensors somewhere else?


Strokers, If your block isn't cracked then the rest doesn't matter as it is a fresh build. I've only seen the far to budget conscience strokers explode. Pick good parts and you'll be fine. And the crate ones with warranty I have only heard great things about.
But up to you.


1. The LS intake will positively affect performance, it is the intake for the sports cars.

2. Might need a cowl hood anyways, but I'm not sure.

3. I would pull the pump and replace with the GM, it will be the easiest solution.

4. Not sure, seems like a lot of work since the XJ cluster is tiny. I would just get some Autometer (or whoever) gauges and mount them to a blank in the dash. Like this http://snsclassics.com/images/dolphin/6blk_red.jpg

5. You skipped 5.

6. I would go 4L65E, But for offroad an auto makes for a much more pleasant ride. Nothing like trying to be delicate on a hill while off camber with a standard.

7. I'm not sure, seems odd though.

6. (your second 6), I would say whatever one has the most aftermarket support in general, and whatever one has the cheapest mounts?



Hope that helps.

Click to expand...

Wait, is there a driveline that I could just swap in complete from motor to t-case, into the XJ? Chev is all drivers drop right? I've seen hints of other guys just dropping the whole lot in and not worrying about adapting bellhousings/tcases... Is this a simpler route?