Driveshaft change 7.25 to 8.75 rear end, what changes needed?

I am going to change from 7.25 rear end in 1976 Dart to 8.75 rear end.
Are u joints different?
What about driveshaft length? Will current 7.25 be too long or short?

I have seen the small to large u joints in the past. Is this all I need?

Bear in mind, this car is staying /6 powered. I do not plan on any 8 second passes any time soon, so a titanium, super duper driveshaft is not really needed.