So how much to shorten driveshaft? I measured the distance with 70 and driveshaft pushed right up against the transfer case there was 2 5/8”.  But I also took out 3 extra leaf springs (someone put them in and it rode like a tank). So now I have the 80 in. Looks like have to shorten driveshaft 1 3/4”. From what I’ve been reading people are only shorting 1 inch. Which is right? Thanks. 

Call the shop that's going to shorten it. They will tell you how they want it measured. That's what I do.

I’ve used this before when shortening shafts for a mud truck or Offroad vehicle. This way I know how much To remove. 
But as said before, call the shop your going to use and see how they want it measured. they might measure it differently.