Rear end mounting question

I found a decent looking 8 1/4 rear from a '92 Jeep XJ and I'm wondering if it will fit in my '74 dodge dart or what modifications I need to make to it fit.
Car currently has a 7 1/4 since it's a slant car and I'm swapping a mildish 340 in it so I wanted to change the rear end. Specs on the 8 1/4 is that it has 3.55 gears and has been welded.