I am about to install an lsd from one jdm y21 tranny to a non lsd jdm y21 tranny. Basically what im doing is taking an LSD from one tranny and installing it into another tranny to make it LSD. My question is do I have to swap over the final drive and keep them matched. or can I just swap over the LSD diff with the final drive on it. Do the notches have to match? Because the Tranny with the LSD on it right now the LSD ring gear has 3 notches and the Countershaft Pinion Gear has 2 notches.
The reson why Im even doing this is cuz the LSD tranny the gears are shot. and the new tranny I got is a non-LSD. with good gears.

thanks