I will confirm, a 1/2 ton axle WILL fit your 52 3/4 ton truck with no problems. I have first hand knowledge as I personally did it to my 52 3/4 ton truck. As stated by ghostrider you will need the 1/2" diamter u-bolts.
Doing this allowed me to install a 5 lug disc brake kit as well as a power steering kit with no problems.
