Full Size Jeep Network

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!

Wow, very nice looking one-owner J20! I've never LS-swapped anything but several members here have done it.

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!

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!

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

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

$650....
Ouch

Sent from my SM-G892A using Tapatalk

SJohn wrote:$650....
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

looks like I can live with the push buttons for now.

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!

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 . 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.

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.

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

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.

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.

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!

Someone decided that the driver side shock mount should be permanent, I disagreed. Cleaned up and painted the frame too.

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.

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

Sent from my SM-G892A using Tapatalk

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?