I have a 1980 model toyota pickup and the price of rebuilding my 20r engine comes dangerously close to the price of a new/rebuilt engine. I am thinking of up grading to at least a 22r, but possibly moving into a 22re. Could any and as many of you please tell me the difficulties that I will run into with installing each of these engines. Thankyou for your time and advise.

 

I'd go with the 22RE and get fuel injection. Niice.
Best way to do this is proably going to be to get the whole donor vehicle.
I don't know if the motor mounts need changed or the trans you have will bolt to the new engine, or if the 5sp and the 22RE will bolt to your t-case, or what, but those are easy to figure out.
The main issue for most people will be the wiring. Get the entire harness from a donor vehicle, get a wiring manual and have at it. It really really really helps if you already understand wiring and therefore a) have a clue what it is that needs done b) aren't afraid the daunting look to the task, and c) will be able figure out how to keep the parts of the harness you need and get it all hooked in. Basically you need all the harness for the engine itself and anything like the 02 sensor etc, the part of the harness that goes to the ECU, and the ECU. Then somehow bring battery power and switched ignition to the ECU, and connect from the new harness to your old harness the wires for things like the air conditioner clutch and stuff, if any. Really, the concept is that simple. In reality its a little tricky, but not all that big a job.
If you go with a 22R you won't have as much to adapt, but I think you will still have a few wiring things to change.

 

the easiest way would be to just put an '81-84 22R short block into your truck and putting the top end from your old engine on it. all bolts up, gets you that extra 200cc of displacement the 22R has.