Seat belt interchange

They do make aftermarket belts that will bolt to the factory locations for the 73 and older. Basically puts the shoulder retracting mechanism on the floor behind/next to the front seat and leaves the lap retractor in the stock location....someone had a post......found it!
http://www.forabodiesonly.com/mopar/showthread.php?t=48125&highlight=Seat+Belt+Install