I don't have a Dually Ram, but the front brake pads on my 1500 also wear unevenly. On my truck the inside pad wears faster. I also have a problem with the front pads wearing much faster than the rears. My truck has 98k miles and I've replaced the front pads 5 times and the rotors once. The rear shoes are still the original ones though. When it was still under warrenty I took it to the stealer to see if the proportioning valve was working. Of course they said it was all working correctly. It does brake the rear wheels when I put it up on stand though? I've also read on other boards that the newer body style Rams have front braking issues similar to what I and your dad have experianced. I jsut make a habit of pulling the wheels off my truck every 5k miles to check pad wear.