New around here, with a "new" '71 short bed

[HalfCaseKustoms]

Hey all, I figured I would introduce myself after a couple weeks of lurking. My name is Casey, from MA. I am an airbrush artist by trade and mechanic/fabricator hobbiest. Last month I sold my '06 Jeep LJ in search of a c10. I found this '71 up in NH, originally from SC and has never seen a New England winter. Previous owner did all the body/interior work. Everything is new except the original 350/3speed manual. Coil drop 3" front and 5" rear. Runs pretty good but that didn't stop me from sourcing a 2005 6.0LS and 4L80e out of a 2500 van. I got the stock harness and computer, PS pump and alt with it too. I think I'm going to use the dirty dingo mounts with poly bushings and cpp adaptors, DT headers, and cpp tranny cross member. I have a good friend who has done a few turboed LS swaps in various vehicles and has modified the stock harness and flashed the ECM. I will be hiring him to do the wiring/tuning.
I plan on finding an automatic steering column/shifter. I guess my only question at the moment is can I use the stock driveshaft? And what do I need to match it up to the said tranny?