Hi Robbie a 3.9 is a good all rounder ratio especially if you've got a 5 speeder. There's little noticable difference between a 3.9 and a 3.78, my old mk2 has a 3.78 quaife LSD and was so much fun , it also has any tramp bars which really gets power down.
My van is all complete now , it drives quite well and occasionally gets thumbs up from passers by .