if you have the stock 7.5in rear end it won't take the abuse of 500tq OR a stick shift. you will want to change the whole rear to something better.
i've done all the measurements but haven't done the swap myself yet but others have---mid 90's
caprice/
b-body 8.5in rears. they are wider by about 1.5in/side but that can be fixed with more backspacing on the wheels. they also have a 5x5 lug bolt pattern, but that can be fixed or accounted for.
or you can get a ford 9in or a GM 12 bolt made for the car.