A-Body Rear end help!

Hey everyone,
Well i have once again (well it finally broke again from my playing around too much younger days) broken my rear end on my 73 dodge dart custom with the factory sized 7 rear end. Im somewhat on a budget and need to find out what other years/models of older mopars will work as a temporary fix until I can afford to buy the 8 3/4 setup i need. I dont want to have to do any modification anywhere. Im mainly looking for direct bolt in.
Also, I have a guy who has a factory rear end from a 1970 duster that he said he would sell me for 200. Would this rear end work on my dart?
Also, if any of yal know where i could get another possibly cheaper (or really cheap) rear end that would work I would appreciate the help!
Thanks in advance guys
Jason R. Brooks

UPDATE: the VIN on the duster is VL2C0B378203. the guy also said that the axle on the build sheet says "343".
Any help is very much appreciated!
Author: moparman485