The "1/2 ton" is the ONLY truck that has the "floating" push in bushings that do not require "outside help". Your 3/4 ton has bushings that press into the knuckle and then reamed to fit the king pin. This link is to your particular front end, but I think it is typical for the 1947-1954 A.D. trucks.
http://chevy.tocmp.com/chevyresto/53130.htm By the way, this is restoration pack series and it is the only place I have found this information. I was unable to find it in the Service Manuals. P.S. Take that axle to a competent machine shop to have that bushing reamed to fit the king pin IMHO
