/6 Driveshaft-8 3/4???

When I install an 8 3/4 rear end would the /6 driveshaft hook up to it? I'm thinking it might be nice to drive the car while I prepare the hemi that will eventually go in the 66Dart. The motor is going to take time partially because of the expense, partially for parts availabilty. So I guess the questions are will the 8 3/4 require a different length driveshaft when used with the /6, and will the original shaft ujoint fit the new rear?

Even if its not roadworthy if i can at least move it around the driveway to get it out of my way when I have to work on other cars. Only one spot in the driveway is suitable for working.

Thanks