I have a 86.5 hardbody, 4 banger, 5 speed, 4 by 4, I'm thinking about adding a/c to it. I came without a/c. I found donor truck at a local junkyard, same year/body and engine. I've converted several vehicles from R12 to R134a but have never tried to add a/c to a vehicle. How much trouble/problems do ya'll think I'll run into? The swap looks pretty easy but I wanted to ask before I dive into it.