Bought a 2001 4Runner last year that had a 3.4 with a rod knock. I took a couple months to swap in a 1UZ from a '91 LS400, as well as Tundra front brakes, rear air bags and ARB front bumper. Thought I would share since I have gotten so much info from forums but never contributed.



I used the a341 transmission from the Lexus, which I disassembled to install the tailshaft from the 4Runner a340. I also used the deeper pan and shift shaft. Of course the TC bolted right up, but the rear driveshaft was shortened 2.5 and front lengthened.






I had to fabricate custom headers and motor mounts. I taught myself to weld a year before, can't believe I waited so long to buy a MIG! Anything is possible...



Here's the rear transmission mount. The secret number is 2.5 inches back from the original position, and a 2" body lift for the engine to fit


Now we need some cooling

And some Tundra brakes, wow so easy and what a difference! I think it took 1/2 hour to install them


So that was the easy stuff, the real trick was wiring. I spent 50 hours studying wiring diagrams and drawing my own schematics, with the goal of every button, warning light and cruise control to work. It all did except the factory tach was off by 2/3 rpm




Power steering bolted right up. I moved the stock radiator lower and made custom hoses. I attached the Lexus MAF to the 4Runner airbox. The oil pan needed some minor mods to clear the front crossmember, but fitment was pretty simple. 2.5" exhaust to a stock muffler, I like quiet.

Fuel economy improved, but the extra 100hp is great for towing and getting on the freeway :-)

 

Nice work, thanks for sharing all the pics and a few useful tidbits.

 

Nicely done!, thats an intense swap!

 

good write-up and thanks for sharing!

 

Wow, impressive! Looks like clean work!

Question: How do you get that to pass emissions, in California, with a non-OBDII engine that's ten years older than the vehicle??

 

that is pretty cool
I take it in your part of California you don't have to worry about a referee inspecting the truck? For some reason I thought the engine had to be the same year or newer than the vehicle it was going into...
I would love to do a 1UZ in my 94

 

I am, however I am about to replace the 3.4 in my '96 limited with a 2001 LS400 with the VVTI and 5 speed auto, and make it smog legal. Then I will upgrade the 2001's 1UZ with the 3UZ and 6 speed auto. Now that I have the fabrication figured out it's really easy.

 

good project to work out the bugs... I admire your tenacity at tackling so many of them
I was unfamilar with the 3UZ, output numbers etc look great on that thing!

 

Very clean swap. I will be putting in a 2005 vvti 2uz from a gx470 into my 2003 taco 4door.

 

I'm sure you know what you're doing, but if you need any wiring diagrams, or have any fitment questions, let me know. Just got my JDM 3UZ this morning, so beautiful!