8 1/4 rear end 2.45 gears!

Oh man more too it then I thought and yes it's de a 8 1/4 rear end I no now for sure. A good dependable mopar guy has a 73 duster 8 1/4 rear a end with the sure grip 3:23 or 3:21 gears in it complete with lea springs. Should I get it? He want 300? Pretty good condition should bolt right up