1985 ls swap

[Blake1999]

Hi I have a 1985 c10 that I'm putting a 5.3/4l60e in I have almost everything figured out just a few questions.

I am using dirty dingo mounts. Will the trans crossmember have to be modified to correct fitment for tranny or can it stay in stock place?

Also will I need to have the driveshaft modified or is it the right length and spline?

This truck has factory a/c and I would like to retain it where can I pull a vaccum source from to control the a/c?

What's the best way to set up the drive by wire in these trucks?

Those are a few questions I have so far thanks to anyone and everyone that can answer them!!