Find a '64-'72 3/4-ton with the 4.11 rear end, and swap that center section into your axle. I doubt that you're going to blow up an Eaton HOxx axle, unless you're going to put a huge supercharger on that 454. As far as I know, all AD 3/4 and 1-ton trucks had open drivelines.
For more on the gearing change, there is another thread active right now talking about it.
