I found a 1985 6.2 4x4 that I am going to remove the motor for spare and put the 4wd on the burb. does anyone know of a write up on this? What things do I need to keep from the donor? Will the shackle mounts fit on the 2wd burb? Any advice would be appreciated.

is this conversion even worth doing?

I think a 4x4 requires a heavier frame than the 2x4. I did a '65 2x4 PU body onto a '63 4x4 Suburban frame years ago and the 4x4 frame was much stouter. Possibly your Suburban body will fit on the 4x4 frame.

Personally, I don't think it's worth doing. I have, on occasion, had brief thoughts of doing that myself, but honestly I think you're better off just finding a 4x4...