I have a '93 4Runner that I plan to swap out the 3.0 with the 3.4, my question is this: can I use a 3.4 WITH wiring and ECM for a 2WD tranny in my '93 which has a tranny for a 4WD? Or do I need a wiring/ECM from a 4WD only?

 

Hope you find your way to our 3.4 swap section. There's a trove of information over there- best on the internet. Now, I think you can do what you're describing. The engine will run fine on a 2wd ECU. You might have to wire in a simple relay to control to ADD front end, or low range on the t-case. I can't recall exactly, but you can read up on it yourself.