I'm looking to put a new rear end in my '56 Fairlane after the stock one locked up on the way to this years Route 66 show. Is there a best year to use?
I'm running a stock 312 and 3 speed overdrive. I want one with disc brakes.  

Take a look at the 8.8" rear ends under the Mustangs and Explorers.  They are narrow enough and can take whatever the 312 dishes out now with no problem. The emergency brakes are alot easier to hook up than the Lincoln and parts are still made and they are cheaper and they have discs!