does anybody know if a 3.0l out of a 1990 4runner with a automatic transmission swap into a 1991 pickup with a 3.0l and a manual transmission without alot of hassel

 

Just taking the 3.0 out is a hassle.
I couldnt imagine trying to swap it
Good luck though

 

You'd have to address the wiring as well as the ECM differences.

Auto ECM's look for different info than manual ECM's.

As far as fit... no problem. Should even be able to swap trannies, just make sure the 3.0 that will be mating to the 5spd has a place for the pilot bearing.

 

It will work fine. There should be no reason to worry about wiring or ECM differences if you are just swapping the engine. You will need to install a pilot bearing for the manual trans, and you will likely have have 1 extra coolant temp sensor (blue in color)that you can just leave unhooked.

 

Yeah you'll want to keep the 91 engine harness in place and just swap the engine. Its more of a hassle that way because you have to remove the intake to get to the fuel injector plugs but its still better than rewiring stuff to the ECU.