Quoting agent23:
has anyone ever welded there front diff because wen i bought my galant it was welded i was told u can kinda tell because its turn radious isnt normal but i guess my question is is where can i get a new diff from
Probably your center diff, not your front diff. Pretty easy to swap out, if you have sufficient tools. You can purchase a 4 spider center diff from Jack's.
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A little spendy at 999 outright, though.