Lilkyle5151

Hey all! First off I'd like to introduce myself and my project 95 4Runner with auto trans. I bought this runner knowing it would need a new motor as a project(has the 3.0). I actually bought very spontaneously as I was going to check out a jeep I was going to buy and this dime happened to be sitting next to it so I asked. He just so happened to want to let it go because it needed a motor and he didn't want the hastle.
I am also what you would call a "backyard mechanic" never certified but I know my way around a vehicle.
The plan for this was to just put a stock 3.0 in but my Toyota friends tell me to just 3.4 swap it. I've done countless hours to of research and end up reading the same few discussions on the swap.
What I've come up with is that the 3.4 drops right in with the 3.0 mounts. I can use my factory 3.0 automatic transmission I just have to use a automatic t100ecu to match shifting patterns(t100 auto trannys used same sensor as 4Runner auto) I would have to use a t100 oil pan for clearance issues. Also hood clearance as motor is taller but I have a 1.5" body lift waiting to be installed so I'm not worried about that. Custom exhaust/crossover pipe also not to worried. I also know I'll need everything on the wiring harness.
My main concern is the wiring aspect of the swap as wiring is just simply not my thing. I know there are companies that make the wiring pretty much plug and play as I would love but I do not see myself paying $600 on a conversion harness. I'm a little cheap. I have heard of members offering to do the wiring for a fee but those were in threads in years past not very current.
I would also like to say I can get a running 3.0 for the same price I can get a 3.4 and most of what I would need. Just the wiring part/expense has me at a standstill on whether or not to put another 3.0 in.

Thanks in advance yotatech!

Gevo

I say, do the swap. Even if you have to fork out the $600 for the wiring. I rebuilt my engine, cost me about $1200, and it's running very well.. but the much improved engine and systems of the 3.4 is the way to go. I'm secretly hoping my engine blows up so I can do the swap

Lilkyle5151

Thanks for the reply gevo! I was thinking about just biting the bullet and getting the conversion. Do you know if the conversion is plug and play? Any experience?

Gevo

No sir, no experience. I'm sure someone will come around soon enough with that info .

Charchee

There is a ton of good info out there but do a search for forums on the swap that have parts lists. You would need to make a parts list yourself as most people do but several folks were good enough to update theirs after their swaps and post them. I can't remember any of them off hand but seek and ye shall find. Making a list will let you associate estimated prices with the needed parts and then add up the cost. To do it right with an auto transmission is going to require quite a bit more than a few parts and a harness. When you find a good swap thread like I'm talking about, you will see what all went in to the swap that was unexpected, especially in the neighborhood of donor parts from the 3.4's previous vehicle.

I won't get into my background but my whole career as a maintenance consultant has been based on examining the feasibility of rebuilds vs. replacements of engines and other major components in all types of vehicles and equipment. I personally ran the numbers on rebuilding my 3.0 and replacing it with a 3.4. I have one of each so it made it easier for me to examine the two vehicles side by side.

Rebuilding my engine in my shop doesn't intimidate me at all. I can do everything myself other than the machine work that is absolutely necessary on an engine made up of an iron block with aluminum heads. The parts are relatively inexpensive when you look at them individually but when you add them all up it's expensive. I came up with a number of over $1300 to do it with the highest quality parts. Folks are going to respond saying that is too high but it's an honest estimate I assure you. That makes a swap look good other than the fact that you are not getting a fresh engine and there aren't a lot of low mile 3.4s left out there. I estimate the cost of a swap to be around $1500 but that's not as scientific of a number as the rebuild.

That being said, the only way I can really make the numbers work on the swap is to buy a wrecked 3.4 vehicle with relatively low miles. If I can buy one for $1000 or less I will be comfortable with the rest of the project. Buying the whole donor vehicle will give you all of the OEM parts that you are going to need and having it parked right next to the recipient vehicle will make things a lot easier as well. Another $500 for a new clutch and some exhaust work and It makes sense to me. You are right about the wiring being a challenge. You are going to have to have a wiring harness so if you decide to pull the trigger on the swap, while you are hunting an engine, see if you can't find a harness at least so you can start planning your custom harness. If you can figure out where all of the wires go, you can have someone graft it together professionally for a whole lot less than $600.

I don't have a sales pitch for you either way. Just kind of wanted to give you an objective opinion on the matter. Folks will tell you how much better the 3.4 is and how much more power it has and how bad the 3Slo is but most of them don't have both of them in their driveway. I like both of them for different reasons and my 3.0 is still kickin it after 212,000 mi. The decision is a lot harder for me but you are going to need to do one or the other.

Focus your research on complete build-up threads from folks that have done it successfully and add up the cost of what you are going to need. Make friends with a few of them so you can ask questions when you get stuck. Find you some potential donors in local salvage yards if you don't intend to buy a complete donor vehicle and most importantly, have fun doing it. If you just want the end result then you shouldn't attempt it. Part that thing out and go buy you a running rig.