Help w/ 7 1/4 to 8 3/4 change over

Hi, I need some expertise on this issue, I have a 66 dart gt w/ 7 1/4 rear end. I want to change to 8 3/4. What years A body 8 3/4 will "bolt right in"??? I have heard many different opinions. Also, what else would I need to make the change?? thanks!!!
DoctorDiff Drivetrain Components has every thing you need.