This is hard to believe, but the NAPA dealers in my area did not have a reamer for a steel axle (they had reamers for bushings). The heavy truck shops in this area (Albany, NY) wanted $400+ to ream an axle (a 1/2 hour to 1 hour, $75-$150 job). I bought a good quality adjustable reamer for under $35, delivered. The king pins are now nice and tight (in the axle and in the bushings/knuckles).
You will need to have the axle reamed and the bushings reamed (on a 1-ton truck).