Jody, you should be able to find brake drums and shoes for the 3/4 ton, but they aren't as easy to find as the 1/2 tons. The master cylinder is the same on either truck and I think the wheel cylinders are also the same, so parts are easily available. The only real issue with the Eaton rear end is that the tallest gears you will be able to find for it are 4.10's. Other than that, it is a great rear end.
To your second question--So If Im reading this correctly you think I can put a 55 or later 3100 rear end will fit into the 1/2 ton torque tube axle?
Nope, that's not what I'm saying. Sorry to be unclear. Forget about using a torque tube rear end because your 3/4 ton doesn't have one. So you don't want to use a '54 or earlier 1/2 ton rear end. Look for a 1955 or later 1/2 ton rear end and it should fit your rear OPEN driveshaft. The front section of the drive line has a torque tube, but you can forget about that and leave it alone. All you have to worry about is the rear section, the open driveshaft.
All 1/2 tons have a single piece driveshaft, either a torque tube version ('54 and earlier) or an open version ('55 and later). All 3/4 tons have a two piece driveshaft. '54 and earlier had a torque tube on the front section. '55 and later had an open driveshaft on the front section. That part doesn't matter...the key for you is that ALL had an open driveshaft on the rear section, so every 3/4 ton rear end connects to an open driveshaft. That's why you need a rear end set up for an open driveshaft, not one with a torque tube.
Hope this isn't clear as mud!
Matt
