The wiring is really not the bad. Toyota used round about the same color of wires between the 2 vehicle even though there is 15 years difference. The 5vz computer is wired to turn on the same as the 22re. It's just a matter of finding the pins you need to use. The body harness,  that stays with vehicle(connector V on my 4runner), has all the power wires you need to use for the computer except 1 for the OBDII plug.  You do need to have the 5vz body harness connector for the computer. It does not come with the engine harness.  This is where the majority of wire swapping goes on. The circuit opening relay is kinda different between the 2 vehicle. The original way it was wired it made the circuit through the air flow meter to keep the fuel pump running when the engine would start. It's a green and yellow wire on my body harness and on the new Tacoma harness. I found the green and yellow wire going into the computer at one of the engine harness plugs, and Teed into it from off the circuit opening relay. I hope that kinda makes since. Evertime I took a pic of it, it came out blurry. I hooked everything up with butt connectors and scotch locks temporarely. I am going back through and soldering when I am sure everthing is where it is goin to be. You must have both Toyota EWD's to do this. It's not impossible if you don't but it would make life a lot easier. The pin location reference is the most help. I'll answer what I can if anybody has a question.

  I also did the Tach mod. Since the motor now has 3 coils the signal needs alittle help. I removed the cluster and the tach and soldered in a 10k ohm , 1/4, 5% impedence resistor. I reinstalled everting and noticed that it was showing about 1000 rpm's more than the motor was actually doing. I had to adjust the potentiometer. Which was pretty cool. All it is, is alittle white plastic screw behind the tach. You have to leave the speedo out and let the engine run to adjust it. It takes very little to get it to move. http://www.yotatech.com/f160/tach-problems-22ret-5vz-195749/

  Also had to make a battery tray. No big deal, just some 1/2 angle and square stock. and the factory hold down had to be altered(hammer and vise) a bit.