1986 J20 LS Swap

Area to show off your Custom Build threads.
Post Reply

Topic author
SJohn
Vendor
Posts: 283
Joined: Sun Nov 03, 2019 4:10 pm

1986 J20 LS Swap

Post by SJohn »

Hi all! My name is Seth, I live in SETX, and currently a senior Electrical Engineering student and rebuilding a 1986 Jeep J20. This is my second FSJ, the first was a 1981 J10 stepside that my dad and I rebuilt when I was in high school. Sold it before I graduated high school, regretted it, and finally bought another one in August! The first build was a 360 to 360 swap which turned out ok but was hardly reliable enough to get me 5 miles to school so this time around I knew I was going to do an LS swap. So I bought a one-owner 1986 J20 360 auto with 90k miles and a pristine interior, got it running and moving then pulled the front clip, engine, transmission, and transfer case! Then I bought a 2006 Chevy Silverado Z71 with 143k miles and an L33 5.3! The plan is to use as much from the donor as possible (engine, trans,tcase, fuel system, etc). I'm definitely going to need some help from you guys but very excited for this project!
Image
Image
Image
Image
Image
Image
Image
Owner/Operator/Chief Engineer of Johnson Production FSJ Parts
https://www.johnsonproductionjp.com/

1986 J20 LS Swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=17875

1981 Cherokee Chief - Rustard - 2JZ swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=22981

twisted frame
Posts: 637
Joined: Wed Mar 27, 2013 9:41 am
Location: Massachusetts

Re: 1986 J20 LS Swap

Post by twisted frame »

Wow, very nice looking one-owner J20! I've never LS-swapped anything but several members here have done it.
73 J4000. 360, MC 2100, T18A, D20, stock closed knuckle Dana 44 front, 60-2 rear. Warn Lock-O-Matics, Warn/Belleview electric winch, true duals with glasspacks, old-school front diff skid plate, used 265 Toyos on 16" AR wheels.

ScramblerCJ8
Posts: 58
Joined: Mon Mar 11, 2019 9:08 pm

Re: 1986 J20 LS Swap

Post by ScramblerCJ8 »

Nice, you are starting a project from two complete vehicles and I figure both of them in good running condition. I'll be paying close attention.
Im doing a similar build on a 1966 j 200 that I got for cheap from a guy that was parting it out, so its just the frame and cab. Got and engine from a 2004 Chevy Tahoe from the local wrecking yard with the ecm and wiring harness. Transmission out of a 96 suburban 4l60E and a 241c t case.
Maybe doing it your way is more economical!
User avatar

DustinLangston
Posts: 597
Joined: Fri Jun 14, 2013 8:03 pm
Location: Cedar City Utah

Re: 1986 J20 LS Swap

Post by DustinLangston »

Wow those are both great looking trucks! I am a little surprised that you'd take a pristine looking newer truck just to gut it. I think there are plenty of rolled over destroyed trucks to choose from. :)
But either way welcome to the forum. I've done a few LS swaps into FSJ's and they are a lot of fun. The GM T-case is the only thing I recommend not using because I love the Jeep NP209 so much! But either way it is a great swap. Good luck!
1982 Wagoneer Limited 5.3L Vortec 4L60E swap - finished/restored - sold - bought back - sold again
1979 Wagoneer 360 TH400 1339 QT - built into perfect daily driver - sold
1981 J10 Sportside Honcho - finished/restored - sold
1979 Cherokee Golden Eagle - 5.3L Vortec 6L80E swap - finished/restored - sold
1967 Super Wagoneer - sold, too much work
1978 J10 Golden Eagle - finished/restored - sold
1962 Rambler Classic Cross Country Wagon - current project, wife's daily driver - she'll never let me sell it

Topic author
SJohn
Vendor
Posts: 283
Joined: Sun Nov 03, 2019 4:10 pm

Re: 1986 J20 LS Swap

Post by SJohn »

DustinLangston wrote:Wow those are both great looking trucks! I am a little surprised that you'd take a pristine looking newer truck just to gut it. I think there are plenty of rolled over destroyed trucks to choose from. :)
But either way welcome to the forum. I've done a few LS swaps into FSJ's and they are a lot of fun. The GM T-case is the only thing I recommend not using because I love the Jeep NP209 so much! But either way it is a great swap. Good luck!
Thanks, the chevy is much worse than it looks. The underside of the cab is rusted out and one bed side is rusted through but mechanically it's solid. Unfortunately the J20 also has some cancer. The usual bedside rust and floor pans but nothing extreme. After some research I realised I wont be able to convert the chevy tcase to manual shifter since it is the auto 4wd np272. I still have the np208 but I'll have to figure out the VSS for the trans. For your swap did what did you do about the VSS?

Sent from my SM-G892A using Tapatalk

Owner/Operator/Chief Engineer of Johnson Production FSJ Parts
https://www.johnsonproductionjp.com/

1986 J20 LS Swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=17875

1981 Cherokee Chief - Rustard - 2JZ swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=22981
User avatar

DustinLangston
Posts: 597
Joined: Fri Jun 14, 2013 8:03 pm
Location: Cedar City Utah

Re: 1986 J20 LS Swap

Post by DustinLangston »

SJohn wrote:
DustinLangston wrote:Wow those are both great looking trucks! I am a little surprised that you'd take a pristine looking newer truck just to gut it. I think there are plenty of rolled over destroyed trucks to choose from. :)
But either way welcome to the forum. I've done a few LS swaps into FSJ's and they are a lot of fun. The GM T-case is the only thing I recommend not using because I love the Jeep NP209 so much! But either way it is a great swap. Good luck!
Thanks, the chevy is much worse than it looks. The underside of the cab is rusted out and one bed side is rusted through but mechanically it's solid. Unfortunately the J20 also has some cancer. The usual bedside rust and floor pans but nothing extreme. After some research I realised I wont be able to convert the chevy tcase to manual shifter since it is the auto 4wd np272. I still have the np208 but I'll have to figure out the VSS for the trans. For your swap did what did you do about the VSS?

Sent from my SM-G892A using Tapatalk
The adapter from Novak that adapts a 4L60E to NP208 has a vss sensor in it.

Sent from my SM-G950U using Tapatalk

1982 Wagoneer Limited 5.3L Vortec 4L60E swap - finished/restored - sold - bought back - sold again
1979 Wagoneer 360 TH400 1339 QT - built into perfect daily driver - sold
1981 J10 Sportside Honcho - finished/restored - sold
1979 Cherokee Golden Eagle - 5.3L Vortec 6L80E swap - finished/restored - sold
1967 Super Wagoneer - sold, too much work
1978 J10 Golden Eagle - finished/restored - sold
1962 Rambler Classic Cross Country Wagon - current project, wife's daily driver - she'll never let me sell it

Topic author
SJohn
Vendor
Posts: 283
Joined: Sun Nov 03, 2019 4:10 pm

Re: 1986 J20 LS Swap

Post by SJohn »

$650....
Ouch

Sent from my SM-G892A using Tapatalk

Owner/Operator/Chief Engineer of Johnson Production FSJ Parts
https://www.johnsonproductionjp.com/

1986 J20 LS Swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=17875

1981 Cherokee Chief - Rustard - 2JZ swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=22981
User avatar

DustinLangston
Posts: 597
Joined: Fri Jun 14, 2013 8:03 pm
Location: Cedar City Utah

Re: 1986 J20 LS Swap

Post by DustinLangston »

SJohn wrote:$650.... Image
Ouch

Sent from my SM-G892A using Tapatalk
Not only ouch, but you also have to get the trans rebuilt because the kit requires the replacement of the trans output shaft.
It's nice to have a rebuilt trans, but if you weren't expecting the expense then the kit plus a 4l60e trans rebuild is well over $2k.

Sent from my SM-G950U using Tapatalk

1982 Wagoneer Limited 5.3L Vortec 4L60E swap - finished/restored - sold - bought back - sold again
1979 Wagoneer 360 TH400 1339 QT - built into perfect daily driver - sold
1981 J10 Sportside Honcho - finished/restored - sold
1979 Cherokee Golden Eagle - 5.3L Vortec 6L80E swap - finished/restored - sold
1967 Super Wagoneer - sold, too much work
1978 J10 Golden Eagle - finished/restored - sold
1962 Rambler Classic Cross Country Wagon - current project, wife's daily driver - she'll never let me sell it

Topic author
SJohn
Vendor
Posts: 283
Joined: Sun Nov 03, 2019 4:10 pm

Re: 1986 J20 LS Swap

Post by SJohn »

looks like I can live with the push buttons for now.
Owner/Operator/Chief Engineer of Johnson Production FSJ Parts
https://www.johnsonproductionjp.com/

1986 J20 LS Swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=17875

1981 Cherokee Chief - Rustard - 2JZ swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=22981

Topic author
SJohn
Vendor
Posts: 283
Joined: Sun Nov 03, 2019 4:10 pm

Re: 1986 J20 LS Swap

Post by SJohn »

I haven't made much progress due to work and school but the chevy organs are almost ready to come out. I hope to have the engine, trans, and tcase out this weekend!
Image
Image
Owner/Operator/Chief Engineer of Johnson Production FSJ Parts
https://www.johnsonproductionjp.com/

1986 J20 LS Swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=17875

1981 Cherokee Chief - Rustard - 2JZ swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=22981

Topic author
SJohn
Vendor
Posts: 283
Joined: Sun Nov 03, 2019 4:10 pm

Re: 1986 J20 LS Swap

Post by SJohn »

In the meantime I have been looking for some wheels to replace the 16.5" factor wheels. I've spent the past week looking for a 17" or 18" oem style steel wheel which has led to much frustration :banghead: . On top of that I want to run a dog dish hubcap which has to work with the manual hubs and the rears must be deep enough for the 3/4 ton axle. So far, Detroit Steel Wheel and Stockton Wheel are the closest wheel options.
Owner/Operator/Chief Engineer of Johnson Production FSJ Parts
https://www.johnsonproductionjp.com/

1986 J20 LS Swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=17875

1981 Cherokee Chief - Rustard - 2JZ swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=22981
User avatar

TurboJ4000
Posts: 113
Joined: Thu Apr 26, 2018 8:47 am

Re: 1986 J20 LS Swap

Post by TurboJ4000 »

Find a set of 80s ford F250 steelies. They hold hub caps and are relatively common. They keep the old school narrow tire look if you want but will also hold a 12.5" wide tire if you want to run one. My brother has a set on his 92 Dodge W250 Cummins with 35s and they are pretty sweet for his truck.
1970 J4000 / Chevy Frankenstein in progress
Soon to be Lq4 6.0 and 4l80e on 35s

Topic author
SJohn
Vendor
Posts: 283
Joined: Sun Nov 03, 2019 4:10 pm

Re: 1986 J20 LS Swap

Post by SJohn »

TurboJ4000 wrote:Find a set of 80s ford F250 steelies. They hold hub caps and are relatively common. They keep the old school narrow tire look if you want but will also hold a 12.5" wide tire if you want to run one. My brother has a set on his 92 Dodge W250 Cummins with 35s and they are pretty sweet for his truck.
Are those 17" wheels?

Sent from my SM-G892A using Tapatalk

Owner/Operator/Chief Engineer of Johnson Production FSJ Parts
https://www.johnsonproductionjp.com/

1986 J20 LS Swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=17875

1981 Cherokee Chief - Rustard - 2JZ swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=22981
User avatar

TurboJ4000
Posts: 113
Joined: Thu Apr 26, 2018 8:47 am

Re: 1986 J20 LS Swap

Post by TurboJ4000 »

SJohn wrote: Thu Nov 21, 2019 8:36 am
TurboJ4000 wrote:Find a set of 80s ford F250 steelies. They hold hub caps and are relatively common. They keep the old school narrow tire look if you want but will also hold a 12.5" wide tire if you want to run one. My brother has a set on his 92 Dodge W250 Cummins with 35s and they are pretty sweet for his truck.
Are those 17" wheels?

Sent from my SM-G892A using Tapatalk

I think so but I might be wrong now thinking about that more. It would have been unlikely in the 80s for them to be 17s.
1970 J4000 / Chevy Frankenstein in progress
Soon to be Lq4 6.0 and 4l80e on 35s

Topic author
SJohn
Vendor
Posts: 283
Joined: Sun Nov 03, 2019 4:10 pm

Re: 1986 J20 LS Swap

Post by SJohn »

Finally got the engine out. This thing kicked my butt, had to torch the body bolts off to lift it off the frame so we could lift the engine high enough to clear the front diff.
Image
Image
Image
Image
Owner/Operator/Chief Engineer of Johnson Production FSJ Parts
https://www.johnsonproductionjp.com/

1986 J20 LS Swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=17875

1981 Cherokee Chief - Rustard - 2JZ swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=22981

Topic author
SJohn
Vendor
Posts: 283
Joined: Sun Nov 03, 2019 4:10 pm

Re: 1986 J20 LS Swap

Post by SJohn »

I also did some more research on adapting the np208. Swapping the transfer case input shaft to a 27 spline and using a clocking ring should allow the jeep np208 to bolt up for a fraction of the price of an adapter kit. The VSS can be handled with a Dakota Digital pass through pulse generator. Also looking into getting the harness reworked. Progress!
Owner/Operator/Chief Engineer of Johnson Production FSJ Parts
https://www.johnsonproductionjp.com/

1986 J20 LS Swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=17875

1981 Cherokee Chief - Rustard - 2JZ swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=22981

Topic author
SJohn
Vendor
Posts: 283
Joined: Sun Nov 03, 2019 4:10 pm

Re: 1986 J20 LS Swap

Post by SJohn »

Someone decided that the driver side shock mount should be permanent, I disagreed. Cleaned up and painted the frame too.
Image
Image
Image
Image
Owner/Operator/Chief Engineer of Johnson Production FSJ Parts
https://www.johnsonproductionjp.com/

1986 J20 LS Swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=17875

1981 Cherokee Chief - Rustard - 2JZ swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=22981

81waggy
Posts: 111
Joined: Wed Mar 09, 2016 7:30 am

Re: 1986 J20 LS Swap

Post by 81waggy »

just a heads up. I pulled the drivetrain from an escalade and put it on my wagoneer. 350tbi/4l60e/gm246 transfer case with push button 4wd. From what I have learned, the push button 2wd hi/4wd hi only engages the auto locking front axle...meaning your front drive shaft is always spinning. I have manual locking hubs on mine so no big deal.
81 Wagoneer with a TBI 350 Vortec.
83 Wagoneer - 360 Quadratrac
69 Wagoneer - 350 Diesel trail rig
70 Wagoneer - 1414x

Topic author
SJohn
Vendor
Posts: 283
Joined: Sun Nov 03, 2019 4:10 pm

Re: 1986 J20 LS Swap

Post by SJohn »

81waggy wrote:just a heads up. I pulled the drivetrain from an escalade and put it on my wagoneer. 350tbi/4l60e/gm246 transfer case with push button 4wd. From what I have learned, the push button 2wd hi/4wd hi only engages the auto locking front axle...meaning your front drive shaft is always spinning. I have manual locking hubs on mine so no big deal.
So the transfer case is essentially awd with a low. Hmmm Image

Sent from my SM-G892A using Tapatalk

Owner/Operator/Chief Engineer of Johnson Production FSJ Parts
https://www.johnsonproductionjp.com/

1986 J20 LS Swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=17875

1981 Cherokee Chief - Rustard - 2JZ swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=22981

Topic author
SJohn
Vendor
Posts: 283
Joined: Sun Nov 03, 2019 4:10 pm

Re: 1986 J20 LS Swap

Post by SJohn »

Any suggestion on gauges and gas tank? Besides the Dakotah Digital what other options are there for late 80's trucks? The current gauges do work, would it be best to adapt for the GM engine or go with new gauges? For the fuel system I plan to use the gm fuel pump from the donor truck but I will likely need a different gas tank, any suggestions? Also any input on the fuel lines?
Owner/Operator/Chief Engineer of Johnson Production FSJ Parts
https://www.johnsonproductionjp.com/

1986 J20 LS Swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=17875

1981 Cherokee Chief - Rustard - 2JZ swap
https://www.fsjnetwork.com/forum/viewto ... 12&t=22981
Post Reply