new user here. just bought a 1990 MM with a welded rear diff. that i hate. what do i have to do to fix this?!?! do i just need a new diff. or will i need a whole new rear end? its a 4 cyl, 2.4L, 2wd with a 5spd manual tranny.

also looking for aftermarket billet or mesh grilles. anyone have a good parts source? im having a really hard time finding parts for my truck. thanks in advance, any info or leads will be MUCH appreciated!