Sure, Anytime you can grab a bigger diff it is good ...For the right price. If it is all original I would rebearing the rear this way it will be good for a long time to come and nothing will callapse of go wrong on you. cost about 100.00 for bearings and seals.
CHeck to be sure the gears are what they are also...the pinion head will have the tooth count for the ring and pinion stamped on it.
Check every tooth for any broken teeth. Another failure spot by alot of people. Spin the rear ...you are buying it so check it out.

jIm