I'm putting A/C from a '89 4runner into my '84 p/u right now.

You'll need a compressor, compressor mounting bracket, discharge hose, suction hose, liquid lines, condenser, accumulator/drier, A/C switch, and the evaporator assembly.

In the '84 - '88 trucks you could get to the area under the dash where the evaporator assembly installs (in place of a duct section that connects the blower to the center air handling section) by simply removing the glove box and its reinforcing bar. I had the whole dash out so my experience was a little different. The wiring harness was ready with unused plugs for the A/C and the firewall had dimples that mark where the holes for the two refrigerant lines and the condensate drain line get drilled. I think I used 1-1/8", 7/8" and 5/8" holesaws.

With used A/C parts it makes a difference if you are buying a working system or one that crapped-out before it got to you. With junkyard parts you can't really tell. At minimum I'd replace the accumulator/drier. Since my stuff came off a real rusty junker I have to replace the condensor and repair the liquid line. I'm also replacing the drier, the expansion valve and the discharge hose. I'm going to bench test the compressor clutch, drain the oil out of the compressor to try to get an idea of its condition, flush it with clean oil and try to reuse it.

I've heard that good resources for new A/C replacement parts are ackits.com and/or rockauto.com. ackits.com also has an auto A/C forum. I priced the all the hoses and a reman compressor at the local Toyota dealer and got a quote of $850 <img src="/forums/images/graemlins/scared.gif" alt="" /> ackits.com sells a complete A/C kit for about $100 less than that. -- Matt