if you've got drums on the back you won't be able to bolt the diff straight in

you can't use the 2wd diff as it's physically too big to match up with what youv'e got on your car

there is a way to get the drum rear shafts to work with the diff but seeing as you need the outputs from the lsd car which are longer on one side it's a lot of fiddling about

find a guy called ratty who posts here, he'll give you the full rundown