Rear end options for '68

[Questadg]

I am looking for a rear end for my 68. My questions is what options do I have? I looked at rear ends from 66 and 67. I have also looked at rears from olds, Pontiac and Buick but they were 71 and 72's. I was also told that a rear from a 72-73 Monte Carlo would work. I did not take the tape measure with me so forgive me for taking the lazy way out and counting on the expertise of the fine individuals on this forum. Any help is greatly appreciated!