Build FJL8T Build Thread

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TLDR:
I plan to swap an L8T and 10l80 to my 1996 FZJ80. Please follow along and provide feedback and advice as you like! I welcome any and all comments, that's how we learn.

Alright guys, I've decided to start a build thread to keep myself on track with this project. I'm not the most computer savvy guy (don't use them for work anymore and I'm out of practice) so don't expect a ton of tables, fancy embedded links or the like. I will, however, do my best to share part numbers and as many photos as I can along the way.

I've been planning this for about 9 months now and recently sold my FJ60 to focus on this project instead. It's currently a better fit for my family and I grew tired of maintaining a 40 year old survivor Land Cruiser that I didn't drive enough.

 

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A little background and why I chose this route:

I bought this cruiser 2-3 years ago from Texas because I wanted one with as little rust as possible. (Don't we all)

It's not triple locked and has 315,000 miles. The PO replaced the head gasket just before I bought it and I spent a ton of money at PartSouq before the tariffs set in getting it up to my standards.

Sadly, I discovered that the cylinder head is cracked above two of the exhaust manifold bolts and it seeps oil which really bothers me so I set out to make a change. I toyed with the idea of pulling the head again and getting a new one but ultimately decided a V8 would be the better choice in the long run.

I have welded but don't have what I would call competent fab skills so I chose the TorFab Gen V bolt in route.

BASIC PLAN:

2025 6.6L L8T (will get into difficulties with this later)
2018 10L80
TorFab engine mounts and adapter
Stock HF2AV
TorfFab PWM fans and shroud
Swap Time AdvanceTech harness
E92/T87A
Dakota Digital RTX cluster

 

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After watching Tor's videos, I spoke with Mitch at SwapTime for some direction. He recommended the L8T since it doesn't have DOD or AFM. I knew I wanted something with the lowest mileage possible and went shopping.

I ended up with an engine from eBay with only 2 miles. Yes, 2. Apparently a train load of Express vans was derailed or something so it only had delivery mileage. The fact that's it's a 2025 came back to bite me due to injector and ECM compatibility but I still don't regret the purchase, it was a fair deal.

The 10L80 is from a 2018 Tahoe and has about 100,000 miles. This is the part of the build that gives me the most pause due to internet hype and mileage but it's pretty difficult to find an early transmission (E92 ECM) with low miles in 2026. If it needs to be rebuilt in the future, I'll deal with it then but I did buy a GM reman torque converter for good measure.

 

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Trying to be proactive, I called around to different tuners about my setup, only to find that in 2021/2022 GM slowly started transitioning the fuel injectors to a narrower 6mm stem from the previous Gen V 7.5mm stem. The new injectors are either impossible or extremely difficult to tune on the older E92 ECM that I now needed to run to use my 2018 transmission.

No big deal, you might say...just swap them! Well, these engines are direct injected, meaning the injectors bores are physically drilled into the combustion chamber. The holes in my heads were too small to accommodate the older style.

At this point I had a few options:

-Buy a set of new L8T heads for a 2020/2021 engine. (Turned out to be basically unavailable)

-Swap L86 heads onto my engine which have the same cylinder bore and basic casting as the L8T. (Available but lack provisions for the extra steam ports in the block deck from the L8T's Siamesed cylinders and I didn't want to risk hot spots)

-Have my heads machined to accept the older style injectors. I ultimately decided to go this route and contacted Katech engineering who seem to be highly regarded with Gen V stuff.

More money than I would have hoped later, they came back beautifully machined. I got a surprise call from Katech that they "accidentally" CNC ported my heads and I owed them nothing for the mistake, so there's that.

 

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Very sad for you that they accidentally ported your heads. I wish more terrible things like that would happen to me.

 

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Very sad for you that they accidentally ported your heads. I wish more terrible things like that would happen to me.

Ha, yeah I was pretty annoyed with myself for overlooking the injector thing so this definitely eased the pain! To be fair the information about late gen V can be scarce and GM forums don't seem to have quite as knowledgeable members, if you know what I mean.

More updates to come later and I'll throw up some parts pictures for everyone to enjoy.

The 1FZ cooling system finally started acting up and I think I have all my parts together so it's time to get started.

 

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There are a couple of interesting quirks to the Express van specific L8T.

All L8Ts come with hydraulic power steering pumps which is a major benefit but these specifically come with a remote reservoir setup which should really help me. The normal truck accessory drives use an incredibly tall attached reservoir that I'm pretty sure wouldn't clear the hood. The torfab kit uses the Toyota frame side mounts and custom block side adapters which seems to make the engine sit noticeably higher in the engine bay than other weld in options I've seen.

Also, they still use standard fixed displacement style A/C compressors as opposed to the trucks which have PWM variable displacement setups. To be determined how much of a headache the compressor wiring will be.

 

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And a few other parts going on.

I plan to use the Delta (old Wit's End design) radiator trans cooler adapters so I can run a combination of hard and soft -6AN trans cooler lines through the radiator as well as an aftermarket cooler. Also using Cruiser Matt's pedal adapter and pad mount.

I bought a Deatschwerks 9201s-1006 fuel pump but I think I'm going to try the stock pump first. I'm not running an aftermarket cam or anything so TBD whether it can keep up. I'm starting with the corvette style filter/regulator combo too but I am open to an adjustable regulator if this doesn't work well. Basically, I'd like to have the simplest components available for the job and keep the engine bay looking fairly OEM-ish.