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5.9 swap Questions

3K views 26 replies 8 participants last post by  David97 
#1 ·
Right, so I have searched, and looked at the FAQs, along with numerous threads and google searches. However I am at times finding conflicting information. So need some clarification.

Background information; 95 Laredo with the 318/5.2. Virtually everything is leaking, so instead of going through the hassle of being without a vehicle to fix such, im opting to just do a 5.9/360 swap. Plus who doesn't want a little more power out of their Jeep?

Anyways, I know I need a z vin 5.9, and Ive found quite a few option at my disposal at good prices. Any z code 360's from what is it 96-01 Dodge ram 1500/2500s and vans should work correct? So long as its a z code motor?

Next is according to the FAQs, for the 93-95 360 swap, "Late '95 ZJs may not need the torque converter because some of them came with '96 flexplate and torque converter." So late model as in how late? Like 6/94+ build date or?

Then to the flexplate. My understanding is Id need a flexplate of a 5.9 ZJ right? Or according to the FAQs I can "oval out" one of the hole and make it work. Not too fond of that idea, so if someone can clarify which flexplates will work without ovaling anything id appreciate it. If there are any other then a 5.9's.

Motor mount, no big deal, be going with Ironman mounts, so just order ones for the 5.9 correct?

And I think lastly (at least the only other thing I really need clarification on) is the ECU. Some say I "need" a 98 5.9 ECU. Others say keep the 318's as it'll work without issue. I believe I read on a thread Ratmonkey said you can use the stock 318 ecu, without issues, but recommends getting it tuned. However you really wont see many issues without a tune. SCT Tuners are out of stock as of right now anyways so that'd have to be put off for now. The other option for ECUs I read was a mopar performance ecu, but seeing as how hard those puppies are to find, I'm thinking the 318 ecu is what ill be using.



As people are helping me with this, ill still be researching and what not other threads and info. Especially ratmonkeys build which I have bookmarked.

Appreciate any and all help, as well as clarifications for the things aforementioned.:cheers:
 
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#2 ·
the 318 ecu will run a 360, but it will run it lean because it doesnt know its running a bigger cube motor than what it was programmed for. best options are having your ecu flashed, or looking for a mopar performance one. i was told this by a chrysler tech who wrenched in the heyday of these engines
 
#4 ·
#6 ·
Sorry didn't read all the way. The only other well documented 360 swap around was ratmonkey, but he went 5 speed (and 5 speed ecu) before he the 360 in as far as I can tell from skimming.
 
#8 ·
All I can find says the a 318 ECU will run a 360 but it may suck after the learning period. All the injector swap thread say it learns based on sensors except for at WOT, but an engine is not an injector.

A 9er pcm won't fly in a 95 because it's odb2, you'd end up rewiring most of the jeep I think.
 
#10 ·
Ah, yeah forgot about the OBD1/2. Hm. SCT needs to get their tuners back in stock lol Definitely don't feel like rewiring...

just keep in mind, a leaner running engine equates to higher engine temps. maybe you could use a 360 ecu from an obd1 dodge truck?
Already looking at what I want/need to upgrade cooling. Should have mentioned that. lol

Wonder if that would work? I need too look into that idea, and see if I can find a answer. If not, ill just play the waiting game.
 
#11 ·
Efan either niner or taurus is a good option especially if it sees trail duty (low rpm work). There's info on using a volvo (i think) controller to get things running really clean.

Compared to the 4.slow the v8's run on ice so I wouldn't worry (yet).
 
#12 ·
Anyways, I know I need a z vin 5.9, and Ive found quite a few option at my disposal at good prices. Any z code 360's from what is it 96-01 Dodge ram 1500/2500s and vans should work correct? So long as its a z code motor?
yes, any magnum 5.9 will work

Next is according to the FAQs, for the 93-95 360 swap, "Late '95 ZJs may not need the torque converter because some of them came with '96 flexplate and torque converter." So late model as in how late? Like 6/94+ build date or?
I don't know. I wrote that FAQ. You are going to have to disassemble and see what you got. You may or may not need a torque converter. My 95 had the later correct one, but heck I replaced it anyway.

Then to the flexplate. My understanding is Id need a flexplate of a 5.9 ZJ right? Or according to the FAQs I can "oval out" one of the hole and make it work. Not too fond of that idea, so if someone can clarify which flexplates will work without ovaling anything id appreciate it. If there are any other then a 5.9's.
Don't oval out the flexplate. Flexplates are fairly cheap, just get the correct 5.9 one. Hughes has them as do many others.

Motor mount, no big deal, be going with Ironman mounts, so just order ones for the 5.9 correct?
yep

And I think lastly (at least the only other thing I really need clarification on) is the ECU. Some say I "need" a 98 5.9 ECU. Others say keep the 318's as it'll work without issue. I believe I read on a thread Ratmonkey said you can use the stock 318 ecu, without issues, but recommends getting it tuned. However you really wont see many issues without a tune. SCT Tuners are out of stock as of right now anyways so that'd have to be put off for now. The other option for ECUs I read was a mopar performance ecu, but seeing as how hard those puppies are to find, I'm thinking the 318 ecu is what ill be using.
The stock ECU will work fine. My 5.9 motor is from a 98 ZJ. She pulls very hard with a 2.5" mandrel bent exhaust and not much else. Well there is ignition stuff and an efan, but that's all bolt on. I often wonder if she has a few more ponies than a stock niner. 95 V8s had the best fuel delivery of all ZJs IMO. You will be fine.

Oh yea, she pinged on hot days pulling grades with the performance ECU. Wasn't worth the trouble.
 
#13 ·
I bought and installed a much horsepower 5.9...375 HP. I didn't change the fan. I did have the performance ecu. Check kolak from my SIG. I regeared to 4.56s and also had thorley headers and a 3 inch exhaust. Don't go cheap and oval out anything...buy new parts and it'll run like a scalded deer.

Hunter
 
#14 ·
Yeah I already looked up the harmonic balancer and flexplate. Probably going to start ordering stuff next week. Ill probably get a new torque converter anyways as well. Think it was only like 130 bucks or something like that.

Anyways, thanks for help clarifying some stuff for me. Appreciate it.

If anyone has any tips/tricks they want to share feel free as well.
 
#16 ·
If anyone has any tips/tricks they want to share feel free as well.
Basically do things that are easy with the motor out that are relative PITAs when the motor is in. ;)

Replace the front trans seal.
Get both EGR gaskets ahead of time.
Do the plenum gasket fix.
Be careful not to bend the CPS bracket when you mate the motor to the trans.

Depending on how many miles on the new motor:
Replace rear main seal, oil pump and pickup. And oil pan gasket of course.
Replace front engine seal (Viton is best) and use the Mopar performance gasket on the timing cover. You will need to buy that gasket separately. If you have ever had to replace a timing cover gasket, you'll understand why to use the best. Low center of page
http://www.mopartsracing.com/parts/ram.html

Check the plugs and do a compression check. If anything is iffy, time to pull the heads. That's easy work with the motor on a stand.

This is the best gasket set I have used
http://www.summitracing.com/parts/slp-260-1865/overview/make/dodge

All I can think of now.
 
#19 ·
Mines not dying, shes still strong for the most part, just leaking almost every where. So instead of being without a vehicle to fix it all, it's just easier to swap in my case. I do beat the piss out of my jeep though. I am not easy on her at all... But she stays strong, reliable, and pulls hard. Just almost every seal is leaking lol

I'm thinking about maybe selling the 318, or rebuilding it, then building it up mildly. After the 360 is in of course. However we will get to that part later don't the road. :laugh:
 
#21 ·
And I think lastly (at least the only other thing I really need clarification on) is the ECU. Some say I "need" a 98 5.9 ECU. Others say keep the 318's as it'll work without issue. I believe I read on a thread Ratmonkey said you can use the stock 318 ecu, without issues, but recommends getting it tuned. However you really wont see many issues without a tune. SCT Tuners are out of stock as of right now anyways so that'd have to be put off for now. The other option for ECUs I read was a mopar performance ecu, but seeing as how hard those puppies are to find, I'm thinking the 318 ecu is what ill be using.
Well, to run a '98 ECU you'd need to convert your '95 to OBDII - no easy task. I can tell you I've been running a 5.9 using a stock '94 5.2 ECU for years with no problems. I changed to the 703 injectors shortly after install.
 
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