1994 FZJ75 -> LSJ75 (build thread-ish) (2 Viewers)

[71harrison]

Ok I'm horrible at consistency in posting or documenting but for anyone searching for info on doing a swap like this, I know its way easier if its its a actual thread so here we go.

BUT FIRST BACKSTORY & BUILD:

So bought a 1994 LHD 1FZ troopy back in 2021, enjoyed camping out my 80-series and always thought troopys were just so cool, especially with the pop top. Always was watching for them and a pretty darn clean example was reposted by Fit so I jumped on it.

Was told it was a ex nato truck that lived in Turkey its life before being in the US (which i know is at least in part true due to an old "fuel-o-mat" fleet fueling unit i found with the turkish gas station listed. It has a terrible respray on it but is fairly clean overall and only had ~160,000 km on it. Its got the 4.11s and factory F&R lockers so that was pretty sweet.

Previous owner did a OME suspension on it and some great looking but horrifically loud Michelin XZLs on. Soon after I got it, did the whole knuckle refresh fun, put on part time hubs (wild it shipped part time t-case but full time hubs lol) and took the entire floor down to essentially bare metal, coated and sound deadened. Only a bit of rust above the fuel tank but generally was super clean.

At the same time fixed once of the biggest issues, no AC. Did a builder kit from vintage air, really not a bad install and works great, just DONT MAKE YOUR OW N LINES LIKE AN IDIOT. I chased the slowest leak of all time for so long then finally replaced all the lines with ones from coldhose.com, and its been rock solid ever since. It replaces the whole setup (heat + cold) only real downside is you loose the outside air pull, its only recirc but that didn't bug me (just be sure to close the massive hole)

Post this finally had the time line up and cut the top off at Fit.

(CONTINUED FOR MORE PHOTOS)

 

[71harrison]

Next was build out the inside, add power, heater, and fridge fun. 200ah 12v cheap big lifepo4 with victron controls and 200w on roof, works great. Have the parts for alt charging but never have installed it as it just hasnt ever been needed.

HIGHLY recommend the layout with 1 side bench, one side tall but a seat at the front, have had like 6 people hanging out in there, it really works well. More so the normal of 2 people + dog means you can actually sit across from each other which i find SO much more comfy.

Got some old wool blanked and sewed cushions then later did interior rear panels to match. Havent done inverter yet but am tempted to + more battery to be able to run an espresso setup out of the back.

Oh and at somepoint I:
- ARB front + lights + winch
- Swapped to Nomad 16s + 295/75r16 toyos which drives SO much better. kinda want bigger tho
- Built out a 4x4labs for the rear. TBH the labs bumper didnt fit all that great for me, i thiiiink i got some wrong parts, but its a DIY so pretty simple to modify.
- Bought scheelmans, I hate how much I love them cause damn $$ but 13+ hour drives and no back pain so I have to say it is TOTALLY worth if you can swing it.
- Tinted everything with air80, SUCH A GAME CHANGER to interior temps, worth it
- Maintenance, but really it ran super well all the time.
- Went on lots of amazing trips

That I think brings us up to swap time, so I'll post that in a bit in the next one.

 

[71harrison]

Ok swap time. I again am really bad at taking photos during stuff, usually just post stuff to instagram if anything, (same name on there @71harrison come hang). For this I'm just going to write down the top of mind important bits I learned for anyone else wanting to do this.

So first off, what were the goals:
1) to be fun and a bit ridiculous. I'm firmly of the belief these are silly trucks, I love the fact that theyre weird here but not rare at all so its not like it needs to be "preserved" so its a perfect truck to just make into something fun.
2) to eat up highway miles. the US West is huge, i love long road trips but there is a lot of milage to get anywhere, i wanted something that wouldnt feel strained doing 80 getting through the 5 or 15 to pretty areas
3) to be reasonably reliable/easy to service, the 1FZ never gave me ANY trouble, its a simple truck and I didn't want to add a wild amount of complexity or difficulty servicing it.

With that in mind, LS felt like the right engine for power, reliability, serviceability. BUT for freeway eating, I wanted an automatic (wife doesnt do great with the manual), and i wanted something with taller gears. This lead me down the path of doing a 6L80 as well.

Now I know people have started doing the GM 8 and 10 speed which would be sweet, but I was a little skittish on electrical gremlins (esp for first full swap) so I decided to play it safe and go with a connect and cruise setup from GM. Yes its more cash BUT in my mind this dramatically reduced complexity, gave factory support for 6L80 (aftermarket is still getting going with that trans), gave me a warranty to get started, and i could do the 6.2 LS3 which is just funny IMO.

ALSO core to my plan was advanced adapters sells the adapter for the 6L80 to h2fa (and h1fa as same pattern) which again takes out more complexity by setting your locations. I got some great advice to try to minimize decisions I had to make and this helped a ton with that.

So with all that, I went with the connect and cruise ls3 + 6l80 4WD setup.

Now important to the lack of photos I have here I gave myself a pretty aggressive timeline, I had buddies headed to expo pnw and thought it would be fun to try to make it to that and camp around oregon after. This meant about 2 months from pull motor to drive 2500 miles, which in hindsight was a bit silly but also I love a deadline to force myself to focus.

Now instead of a step by step, i'm just going to give a list of issues/interesting things I dealt with/learned. These are all the things I wish I'd known going in that tyou just learn by doing.

I'll film a video of the setup too as that'll be easier to show and what you all probably want to see more.

In no particular order:

• There is not enough space above the fuel tank to do much in the way of in tank pumps without it being almost entirely recessed. I tried this and failed as even tight 90s on the top of the sending unit hit the body crossmember above the tank. Lowering tank would interfere with the driveshaft so instead i ended up running an external pump. You can use compression fittings on the original fuel lines and just adapt them to -6 and be on your way (or just normal fuel lines and clamps lol). This has worked great so far. I've heard stories of external pumps failing but I've also heard lots of success. My understanding is these pumps typically do NOT like to pull, just to push, so I mounted mine low on the trans cross member and just carry an extra.
  • If I was to do this again I mightttt run an internal pump to a bulkhead on the side of the tank? but tbh that feels less serviceable and swapping just carrying a spare feels more reliable.
• The advanced adapters adapter works well but technically moves the tcase back and down just enough that you do need to:
  • shorten rear driveshaft ~1.75 inches (front actually still work works but should probably ideally be lengthened)
  • notch the tubular crossmember behind the tcase. It already has a indentation from factory, I cut mine out, cut the notch ~.5 inch deeper and then re-welded it back in. kinda hard to reweld back in but doable.
  • with these changes its not hard at all to drop the trans/tcase and you can do this while leaving fuel tank installed
• A electric fan from a 2016-2020 ZL1 Camaro fits the original radiator SO WELL if you trim off the tabs. Like amazingly well with minor mods. This is a 850 watt SPAL brushless pwm fan that just RIPS. I got it off rock auto for reasonable price. SO good.
  • You can buy the plug for it or this harness which was great and then this PWM controller is SO cool and really easy to use. It piggybacks on the factory ECT sensor, is standalone, fully programmable, and supports fan up for AC.
  • Motor temps were perfect sitting in bumper to bumper traffic 95 degress + with ac blasting.
  • Honestly this is one of my favorite finds of the entire project, it worked so well.
• Holley midmount accessory drive isnt necessary but damn its so nicely done and packages wonderfully. littttle bit pricey but for all new nice stuff I cant complain that much. The integrated mounting of all the accessories on the waterpump is just so slick. I'd buy again.
• I am not 100% sure its needed but I found a fair bit of concern out there on the stock pressure of the 1fz steering pump and the type 2 gm pump. Essentially that the new pump puts out a fair bit more pressure and this can blow seals on the box? No clue how much truth, but I didnt end up getting a pressure reduction kit I think I went to 1000 psi (or 850 i cant remember exactly) but it was a very easy install and has more than enough pressure where steering feels totally normal so seems reasonable? Not long enough to see if seals get messed up yet but maybe worth it. Also pretty easy to change later if needed.
• The high pressure side of the Toyota pump requires an M16 x 1.5 Inverted Flare if you want to adapt it to -6 which I did. I believe low pressure is m17 if you want to adapt that too but i left the original fitting to go to cooler.
• You have some adjustability with engine height, and left to right (depth being set by adapter and factory cross member) I went kinda "middle of the road" but a fewww thing to watch for:
  • Tube headers get too close to the steering shaft or at least Summits generic set does, specifically the 3rd primary back. I think some sets would likely work but I ended up swapping to the hooker cast swap setup and they fit great. (also I've heard cast is technically a bit quieter and cooler so not bad? Engine masters video says log primary vs individiual looses just a couple hp so I feel ok about it)
  • You do get fairly close to the front third member, its right on the edge of ok but holley does set an "off road" pan that has the perfect shape to address exactly this, I felt it was worth for peace of mind.
  • hzj drivers side battery tray fits wonderfully (doesnt with 1fz due to interfereing with PS rez)
• If you take your time to prune original harness, you can avoid almost all wiring needs that would pass through firewall. like you could literally just run pedal wires though if you wanted. Main ones to use are
  • The original starter signal circuit works great for new starter. Obviously run a new line for power but the signal wire is easy especuially as starter circut is divorced from engine harness
  • There are several ignition circuits in the engine bay but the onces meant for the the old coil are perfect for ignition. 12v
  • If someone is doing this and wants help I went though all the old wiring diagrams and can happily help ya.
• Exhaust routing is a bit funky? Original goes over the frame rails in the bay then runs down the side, this didnt seem doable IMO so I snaked it right behind rear mounts for front leafs, seems reasonable I think? I'll show more in video.
• Automatic transmissions produce a lot of heat. Lol I know some of you are thinking "uhhh duh Harrison", but damn I kinda underestimated this. I originally mounted my trans cooler up behind the fuel tank, no bueno. That area got too hot from exhaust and seems to be very much in a spot of dead air. I had to put together some janky mount to drop it down to get air to not overheat trans, planning on moving to the front asap. TBH no idea why I thought under was a good idea, just an oversight on my part.

I think thats most of it for now, I'll get a video soon walking through it all and for some sweet sound (its rowdy) but back to the plan of expo, I nearlyyy made it haha, Ran into some issues (possibly self inflicted possible doa parts) and was a bit late but essentially did most of my break in miles driving from LA to Bend then went camping in Oregon. Thanks again @Willis for letting me invade your spot for oil change and some quick fab work.

Lots of little bits to still finish off but I'll attempt to keep updating as I finish stuff out, but damn it is fun to pull 80 with the ac cranking over the grapevine no problem. Its a fun truck, I kinda wanna swap another one.

Happy to answer whatever questions

 

[Willis]

This is nice to see. I wanna LS swap my next troopy

 

[davegonz]

Great build! I'll be interested to see what kind of mpg you can get with the LS.