Hi Jacob!
I know it's been a while, but have you made any progress with getting ac into your truck?
I have an 89 gmc k1500 that I need to do the same thing with. A few shops I have visited all guided me to doing the work myself. First find the correct mounting brackets for all the under-hood items, get the compressor, condensor, dryer/evaporator mounted. Then pull the dash and drop the heater box, add the condensor to the vacant spot, drill the holes in the firewall. Make sure the venting controls work of course, whether they are cable-actuated or electronic (mine are cable), so you can route the air away from the heater core and on to the condensor, and of course so you can direct your air where you want it to go. Then just wire a toggle/on/off switch to place/mount somewhere on/under the dash to turn on the compressor/activate the clutch. At that point I would take it to a shop to have them plumb it and charge the system.
It's a huge job, but doable. I hope to hear that you have done so, or something similar, with good results.
