I know this has been ask a billion times but I have the opportunity to purchase a parts truck and need it gone quick. My truck is a 86 and the parts truck is an 83 with same gears as my truck.
Question is how much crosss-sourcing is needed? My general Idea is to use the front axle, shocks, springs, and drive shaft. I'm assuming shock mounts and leaf spring mounts are the only things that need to be welding. Steering should just connect to the pitman arm no issues?

 

No, the 83 has push pull steering, not crossover. Besides getting and axle and drive shaft, you still need a crossover steering kit, spring hanger, shackles etc. stock 83 leafs won't clear crossover steering.
You're not really getting anything out of buyinng a complete truck vs just the front axle and drive shaft, most of the parts won't be useful to you.

 

You may be able to use the 83 rear springs up front.