Here we go... 5.3 LS Swap Thread 1993 fzj80

[Wisco80]

Hey y'all, I'm a 24 y/o husband and dad trying to build my dream truck. Not a ton of mechanic experience, but recently did a timing chain job and a transfer case rebuild job that gave me a lot of confidence in my ability to figure it out. I have friends with lots of mechanic experience including swaps and rebuilds to ask questions to and help along the way. Looking like I might have access to a large shop and lift also for this. So, as the itch grows, I'm going to start gathering information and parts to hopefully attempt the swap this year.

Reason for swap: Better fuel milage, I want to daily this Cruiser as well as take in on cross-country road trips. More power, and amazing V8 exhaust sound. I don't want new vehicles, I want this truck to last me 20 years.
Cost: Goal is around 5k. I will be doing all the labor myself as well as some unpaid mechanic friends. Cost might go over depending on if I get a custom harness, and how much a shop charges me for a fully custom exhaust.
Engine: gen 3 5.3 LM7 or L33. I really like the idea of the L33 and found some for sale around 100k miles for $6-700ish. I don't want to rebuild the engine, but I will replace seals gaskets and timing components before installing. I will also be installing all new accessories on the 5.3.
Transmission: 4L60E or 6L80. While I would prefer 6 gears, 4L60 seems to be way more plug and play as far as wiring and ECU goes. If anyone has information on this I would love to hear it.
Adapter and Transfer Case: stock Tcase with Marks adapter.
Wiring Harness: Not sure if I should get a parts truck and retrofit the GM harness? I don't really know what the difficulty on that is, some youtube videos I watched made it seem there's only a few things you have to retrofit (AC, gauges, etc) Also I believe I have to keep the stock ECU? Or should I purchase a custom harness from PCI or someone? I'm willing to make the investment if it removes the guesswork.
Method: Because I am also doing a full restoration, painting the engine bay, treating the frame and axles for rust as well as coating, replacing the body mounts, I'm gonna just pull the body off the frame. I want to be through as I live in the rust belt and I want this truck to last me 20 years. In theory this should make a lot of things easier such as pulling the engine and mounting the new one.

I'm new to MUD and am not very good at finding the important information and write-ups, if you know of some good information, I'd appreciate it if you could link it to me here!
I will be documenting the swap and restoration on the Instagram account @5.3cruiser and will eventually compile a YouTube video or two.

I'm the newbie to all this stuff so feel free to correct me or point me in a different direction if you like. Any help is greatly appreciated!

 

[SoTexCruiserDoc]

Sounds like you’re off to a solid start amigo! You’re in the right place. Here, the experts have experts and the resources are limitless. We love pictures. A tip on the topic searching…the MUD search isn’t great (IMO), so google your search and include “IH8MUD”.
Good luck!

 

[Wisco80]

Sounds like you’re off to a solid start amigo! You’re in the right place. Here, the experts have experts and the resources are limitless. We love pictures. A tip on the topic searching…the MUD search isn’t great (IMO), so google your search and include “IH8MUD”.
Good luck!

Thanks for the tip! Hope to find a swap where someone removed the body first.

 

[NeverFinis]

Good luck! It is very much worth it in the end.

There is a huge thread dedicated to V8 swaps.

To keep the costs down, I suggest buying an ebay/Amazon harness.

I modified the harness that came with the engine, but it took a ton of time mapping all the circuits, and then matching them to the Toyota wiring. A quality harness is very expensive.

Buy @cruisermatt 80 series water temp sender. It fits better than using an adapter + water temp sender.

You can also use CruiserMatts engine mounts. Here are all the swap parts he sells.

The Toyota Tach can used directly, just some minor modification/adjustment. No need for a Dakota Digital.

I did use a Dakota Digital Gear Shift Unit to map transmission gear to dash lights.

I would advise against pulling the body. It is already a massive project and the chances of finishing reduces as the size of the project increases.

Pull the body when you finish the swap.

 

[Wisco80]

Good luck! It is very much worth it in the end.

There is a huge thread dedicated to V8 swaps.

To keep the costs down, I suggest buying an ebay/Amazon harness.

I modified the harness that came with the engine, but it took a ton of time mapping all the circuits, and then matching them to the Toyota wiring. A quality harness are very expensive.

Buy @cruisermatt 80 series water temp sender. It fits better than using an adapter + water temp sender.

You can also use CruiserMatts engine mounts. Here are all the swap parts he sells.

The Toyota Tach can used directly, just some minor modification/adjustment. No need for a Dakota Digital.

I did use a Dakota Digital Gear Shift Unit to map transmission gear to dash lights.

I would advise against pulling the body. It is already a massive project and the chances of finishing reduces as the size of the project increases.

Pull the body when you finish the swap.

Thank you! I am willing to use a cheap harness as long as someone can refer one that is trustworthy.

And I will most definitely use cruisermatts engine mounts.

I see your point on pulling the body, it does seem on projects like this people loose steam and take long breaks. I guess it's probably not that much more difficult to fit the engine with the body on, but I will have to pull the body at some point to satisfy my OCD of wanting everything freshly painted like it rolled off the lot lol

 

[cruisermatt]

I would advise against pulling the body. It is already a massive project and the chances of finishing reduces as the size of the project increases.

Pull the body when you finish the swap.

This x100. Do the swap, drive it for at least a year then do your frame-off resto.

Before you order send us an email and we can do a bundle discount.
Matt

 

[NeverFinis]

Thank you! I am willing to use a cheap harness as long as someone can refer one that is trustworthy.

No idea about trustworthy, but I have seen Nathan Wei post about harnesses for sale on ls swap facebook. Looks like he is no longer a member. I have seen posts that speak to the fact that most are good, and some might have issues with pin wiring being mixed up.

Nathan Wei Performance LS Stand Alone Harness | Custom Wire Harness

Nathan Wei Performance store is custom wire harness manufacturer, specialize in the production of LS series Gen III and Gen IV standalone wiring harnesses, including 4.8L / 5.3L / 6.0L / 6.2L with Mueltec / EV1 / EV6 connectors for car and truck.

nathanwei.com

 

[Wisco80]

Trying to decide what transmission to go with.

I definitely am going Gen 3 with the engine, as I don't want to have to worry about AFM or DOD crap.

Should I go 4L60E, 4L80E, or 6L80?
- 4L60E doesn't seem very robust based on my experience with it in my 4.3L s10, but is the most cost effective and simple, no complicated flex plate or spacer situation.
- 4L80E is more robust and still gen 3 hydraulic and not electronic, what would have to be done to fit this to the 5.3? If it changes my powertrain length do the trans mounts and everything still match up? Would I need a shorter driveshaft?
- I have the same questions about the 6L80 as far as mounting to the engine, crossmember and driveshaft length. Are the marks adapters made with all this in mind?

 

[NeverFinis]

I went for the 6L80/90 for the 6 gears. and the lower 1st gear, 4.02, compared to the 4L60, 3.06.

Overdrive is about the same between the 6L80/90 and the 4L60. You could think about a 4L65.

I don't think you will have to change driveshafts with either transmission, depending on lift.

Marks adapter will position the transmission about right, but the 6L90 is longer than a 6L80 by 35mm, requiring redrilling the crossmember.

The 6L90e requires modifying the output shaft, or finding the correct one (I couldn't find it). I had mine resplined. Personally, I think 6L80 is the better bet due to easier installation.

Can you use a 6L80 with a gen 3 engine? Not sure.

Looks like Mark's 4WD is now selling a 6l80/90 kit with new frame engine mounts for international markets... nice...

 

[Wisco80]

Pretty sure I Do Cars on youtube did an gen 3 LM7 with a 6L80

 

[alia176]

I'm curious what the actual cost will be vs your $5k target cost. I'd start with a spreadsheet and fill it up with all the bits you'll need to buy. This thread might already have a spreadsheet that you can use, or at least have $$ figures that you might be able to use. It's in the sticky section up top.

Registry - 8x Series V8 Swaps

forum.ih8mud.com