Started removing the 3.0 this afternoon from my 4x4 runner. Hoping to have the 3.4 installed and running by the end of next week. Was planning on waiting till January but all the parts are here and I couldn't wait any longer. I will update this at the end with a detailed report of how it went.
I bought the ORS conversion harness but plan to fab or use everything else from one or other of the two engines.

Got the 3.0 out yesterday.

- Reworked the oil baffle from the 3.4 to allow the 3.0 oil pick up tube to fit. This is easy. The 3.0 pick up tube fits nicely.

-Used the 3.0 oil pan. Fits with no rework.

-I left the 3.0 AC compressor in the engine bay still hooked up to the line. This way I will not have to service the freon when the swap is complete. I will install the 3.4 clutch and pully on it because the drive belt style is different. Not hard to do.

-Moved the 3.0 oil sending unit to the 3.4. No rework required just put it in.

-Removed the 3.4 dipstick plug and installed the dipstick block fitting from the 3.0. These are just pressed in and can be tapped out of the block from the bottom with the oil pan off.

-Used the oil dipstick and dipstick tube from the 3.0. Cut the upper attach bracket loose and rewelded it in a new position to allow it to clear everything and still bolt up.

-Used the two engine mounts from the 3.0. The 3.4 mounts are longer and appear to be a slightly different angle.

Should have the 3.4 bolted in place this afternoon.

- Engine is in and transmission bolted up. bolts up same as 3.0. I found it was handy to have a 10mm x 1.25 tap to clean out the previously unused holes on the 3.4 block.

- Changed the pulley on the AC compressor and bolted it to the engine. Left the compressor hooked up so now I feel smart for not having unhooked the compressor. Now I don't have to service the freon. lol Used 3.4 compressor pulley and the 3.0 compressor, attached to 3.4 AC bracket. The mounting bracket is some lower on the 3.4 than the 3.0 but it still bolts up fine.

- Power steering pump bolted up and hoses connected. I used the 3.0 hi pressure hose and the banjo fitting bolt from the 3.0 on the 3.4 pump. Fits nice.

- Heater hoses on the back of the engine. Used the stock 3.0 hoses. Fit is not super but I like it well enough to leave it.

- Starter, used the 3.0 starter.

- Alternator, Used the 3.0 alternator and 3.4 attach brackets upper and lower. On the lower bracket I used the bolt for tightening from the 3.0 bracket. I cut the end of the lower bracket off near the end to give more clearance for the steering column.

- Crossover exhaust. Used the matching tubular crossover from the tubular manifolds off of a 2002 Tacoma. It drops down on the right side. Required rerouting the fuel line and fab of some heat shields. Used the heat shield from that is no longer needed from the left side as material. I know it would be much easier to buy a crossover and drop it on the left but I really want to try this tubular exhaust setup.

did not work long today and will put the project on hold until Monday. It is looking better with each loose end that gets worked out.

Today
- Oil dipstick and tube. Used the 3.0 dipstick and tube. Had to cut the attach bracket off of the tube and reposition and reweld it to the tube. It now bolts up to the head at the same place as the wire harness standoff bracket on fwd left of engine.

- Alternator belt. Used a 42" belt. This keeps it from being too close to the steering column. Parts clerk said this showed on his computer as the stock 3.4 size. hmmm

- Airconditioner belt. Used stock 3.4

- Power steering belt used stock 3.4

- 3.4 engine harness. I removed the round rubber firewall seal/grommet from the 3.0 engine harness and put it onto the 3.4 harness so it would fit in the hole like factory. I had to make a small cut in the narrowest place to let it slip over the large connectors. The cut is not so large that it can not be easily secured with electrical tape upon final installation.

- ECU, located and hooked up the ECU to the engine harness and to the ORS conversion harness. Then did a prliminary routing of the ORS conversion harness. This is a head ache I'm glad I avoided tackling on my own. I can recommend the ORS harness. It comes with installation instructions and is complete with OBD II connector. Everything fit into the stock location of where the 3.0 ECU had been. I did rework the body harness in the area of the ECU to make it more flexible and I removed the plastic bracket holding the two body harness plugs to allow the ORS harness to rest in that cavity behind the ECU outboard.

- Fuel return line. Used a 4 foot piece of rubber fuel line to route the fuel behind the engine just below the heater valve, etc and to the metal fuel return line on the passenger fender well.

- Radiator fan. Used the 3.4 fan and clutch. Either the 3.4 or 3.0 will fit but I noticed the 3.4 fan was a little larger diameter. I figured this may translate into more cooling airflow. I do not have a shroud so I can not say if it would be a fit problem. My shroud broke a while ago and I have never replaced it.

So far the installation is leaving the engine bay with more room than it had with the 3.0 in it. The factory tubular exhaust is neat and compact making for a very clean looking engine bay. It does not have all the junk hanging off it like the 3.0 does.

The access to the starter is amazing, you can reach right through the wheel well and easily pull it out or put it in.

Started the actual swap last Saturday. So far have spent just under 30 hours working on it including pulling the 3.0.

GOOD WORK man this is the fastest swap i have ever seen! besides my 2 day 5 speed swap but i did a month of homework

I have been planning it for the past year so I would hopefully not have too many suprises. So far so good. Not pioneering the mod or breaking any new ground just following what others have done.

If there ain't no pics, it never happened!!

<img src="/forums/images/graemlins/cyclops.gif" alt="" /> <img src="/forums/images/graemlins/pfft.gif" alt="" />

I don't know how to post pic's.

Today

- Fabbed the exhaust down pipe from the crossover. Used the stock down pipe flange and some cutting and welding. First O2 sensor is in nearly the stock location for a 3.4. Still need to make the line from the down pipe to the cat which is in the stock 3.0 location.

- terminated the electrical connections and finalized the routing. Saldered the wires instead of crimping. Just a personal preference.

- hooked up and bled the clutch.

- Fabbed a new fuel line from the fuel filter to the engine flex line. Rerouted the line to clear the exhaust.

Planning to start the engine tomorrow. Maybe ready to drive by thursay or friday.

Givin' ya a hard time :P

BTW, it's in the FAQ.

GL on the startup, hope all goes well!!