1UZ-FE Engine Swap?
 

Hey All!
I've got a 2nd Gen ('95) 4Runner 4x4 with a 3VZE V6 engine, manual transmission. I absolutely love the truck and plan on keeping it regardless of price and turning it into an adventure truck (lol). My only gripe about the truck is the engine. Frankly I am tired of having to downshift to make it up normal inclines at a normal speed ... and forget towing anything. The power is just so low.

So I've been looking into replacing the engine with something with a bit more juice. The two engines I have come across are the 3.4L 5vzfe swap and the 1UZ-FE swap. I was wondering what everyone's opinions were about the two swaps?

I have heard that the 3.4 doesn't really add that much power but is much easier to install. (the opposite being true for the 1UZ-FE). Do any of you have experience with one or both of these swaps? I'd honestly like to have enough power to not worry about most inclines while towing. Would the 1UZ-FE do that for me?
Also, I've heard that the 1UZ-FE is cheap and one of the best engines Toyota has made. Is that true?
Would I run into any problems connecting a new engine to a manual transmission?

Thanks guys! Appreciate the help!

The easier swap is the 3.4 and the 45HP increase and added reliability is well worth it IMO. Some may say that's not much but considering the amount some will pay for 10 extra HP it's a big deal. If it's not enough they also came stock with superchargers.
https://parts.olathetoyota.com/blog/...ing-30l-to-34l

Do be clear in your own mind as to your expectations when towing. What kind of inclines and what kind of towing loads do you expect to be able to handle with minimal downshifting?

Even my 4.7 liter V8 (265 hp) in my 2006 4runner downshifts to 3rd (from 5th) when going up mild-moderate inclines towing a 3000 lb trailer. That means it's running about 3600 rpm at 65 mph. It's just the nature of things. Engines don't make much power at low rpm's, so you have to downshift to get the rpm up and get into the power band. If you want your truck to loaf up a hill towing a trailer at 65 mph turning 2500 rpm, you'll need to figure out how to put a 6.0 liter diesel into it.

That makes sense. I don't expect to be able to bomb up a hill with a trailer, however right now I get passed by semis going up moderate inclines without towing anything. I'm concerned that if I go with the 3.4 liter v6 I'll still be experiencing that frustration.

From what I remember reading, the 1uz isnt an easy swap with a manual trans because the v8 was never offered with one in north america so, finding a bellhousing that joins the 2 has to be done from (I think) an Australian car and (again I think) there is an issue with the auto trans computer being integrated with the engine computer and not liking that the auto trans isnt there so, it throws a CEL and maybe puts the engine into to limp mode.

The 3 4 is a damn good engine that will bolt up to your truck and trans and that swap has been done 100s of times over. If you do the 3.4 swap and it still lacks power, there is always the possibility of adding the supercharger.

Its balancing how much work you want to do and how much money you want to spend vs you expected results. Do you have the stock size tires? If not then the difference between 235's and 31's can be night and day with any extra load on the rig. Gearing is probably the most important thing to make sure is correct when pulling a trailer with a low powered rig, Well actually its probably brakes but for your question look at gears to tire size. I had no problem towing 2500# behind my last 85 but I was not afraid to give it some RPM's up hills. I see plenty of 3.4 3rd gen runners pulling small trailers on the road and they seem to manage just fine.
Your drive train is the other thing to consider. Back in the day NWOR used to sell adapter kits for a chevy 350 to bolt up to the W series trans. And it usually turned into upgrading the entire running gear because its only designed to take so much power.

I've driven both. The 3.4 definitely pulls better than the 3.0, particularly at lower rpm. But to be honest, neither engine has much spunk until you get above 3000 rpm. When I drive I-70 west of Denver with my 3.0, I spend a good deal of time in 3rd gear at 4000 rpm getting up to the continental divide at 11,000 feet. It will hold just under 60 mph at that rpm and gearing. The good news is that you can't hurt a 3.0 running it that way.

In the past I also considered the 3.4 swap, but my 3.0 refuses to die, and runs like it just came off the factory floor. Other than getting up the big hill west of Denver, it pretty much does everything I want, so I've just resigned myself to looking at the scenery more and chilling out on the long upgrades. I don't tow much with it anymore - I use the '06 V8 for that now - but in the past I've towed our 2200 lb pop-up with it across the mountains several times. It was definitely slow in spots, but we never failed to get there. (It actually towed the trailer better than my '88 Suburban, which would consistently vapor lock on the long upgrades and leave us either sputtering along at 15 mph, or parked on the side of the road until it cooled down.)

The 4.0 1UZ-FE is a dramatic upgrade in performance compared to either of the 90's era V6's. If you could make it fit and work, you'd have an impressive 2nd gen 4runner. As far as drive train goes, I doubt there's much to worry about. The 8-inch rear diff has stayed pretty much the same through the 4th gen's, and the guts of the VF1A transfer case hasn't changed much either. The RF150 tranny is very strong as well. I'm not saying you couldn't break things if you got really heavy-footed, but you'd have to work at it.

I'd check with Advance Adapters to see if they have anything that would help you do this.

I just checked the Advance Adapters website. No adapters for a 1UZ-FE to an R150, but they do have an adapter to mate either a 4.3L GMC V-6 or a small-block Chevy V8 to the R150. A 4.3 GMC V6 doesn't offer much performance above the 3.4L Toyota engine, but a small-block 5.7L Chevy would certainly be an interesting modification. I have no idea what other cutting and fitting would be required to shoe-horn that engine into a 2nd gen compartment.

85toyman's shop has adapters
http://northwesttoysllc.com

what exactly are you towing?
I have been towing stuff from 1,000 lbs to 18k for 35 years.
personally I would not tow anything more than 2500-3000 lbs with a 2nd gen 4runner. They just weren't built to do it

The torque numbers on a 350 will be better for towing vs a 3.4. HP makes almost no difference in towing. And with the 350 being the Kleenex of motors there are tons of cheap bolt on mods or most of the time just a better cam.

But as Dropzone mentioned these rigs are kind of maxed out towing wise around 3000 pounds. They dont have the brakes or suspension for it. If you need to tow heavy stuff you might be better suited to get a used fleet 2500 domestic gas pickup. Unless your going to be towing all the time the diesel motors are normally way to expensive to justify. But you could probably easily find a mid 90's 2500 fleet truck for about the same of leas than you would spend on an engine swap. Probably under $3,000.
I pull 7-9000 pounds too often with my 5.3 1/2 ton Chevy. Am I leaning on it? Sure. But its towing and its not a race. Most accidents I see with trailers involve brodozers rolling coal going way to fast. "Because they can".
Towing isnt about speed. Its about control and brakes. Anybody can go fast but stopping is the art.

Thank you guys for all the gr

Thank you guys for all the great info! I really appreciate it! I am not 100% sure how much I want to be able to tow, I just want a truck with a wide-range of capability. If I need to tow more I can always upgrade the suspension and brakes.

I have looked at northwesttoys and they seem like a great place. Does anyone here have experience with them?