so if i take out the rear end of my 120y (drum to drum) the ute rear end will bolt right in? are the leafs in the same spot? will my tail shaft still fit aswell?

If it's a sedan, you'll need to make up some brackets to mount the shocks onto.
Is it a 210, or a 310?

210 4 door sedan.

you'll need a ute tailsharft

Ok Dats-me correct me if I'm off base here;
But why on earth do you want your car to slide more in the dry or wet? If it's a track car this = slow. If it's for street use this will turn out to be an episode of "car meets tree" rather quickly.(soapbox over)

Now with that said a LSD is the way to go , you have two routes to get one for your car. Wait for a H150 to come up cheap (could be a year or more) or convert to the H165. Price out all the H165 parts and your time. If you can get it done for less than say $1000 then get the H165 if it's over that your 2/3rds the way to an H150, so save the cash up and wait.

Tom