DHD/Dana 80 swap

Alright guys getting ready to tear the truck apart and just want to make sure I have all my ducks in a row since I'm fairly new at this. Like my sig says I've got an ecsb with a leaking dld and an open 70 out back and I'm looking for longevity on the street/track (building drivetrain before engine). I know for the 80 I'll need the plates for the bottom of the axle tubes as well as the plates that sit on top of the leaf springs and the dhd I got off an auto truck so it should go right in. Just curious if anyone on here know right off hand how much I'm gonna need to shorten my driveshaft or if I'm missing anything with either swap. Thanks again