On my 1953 4400 the new front tires are SAMSON HI-WAY-EXPRESS 7.50 X 20 12 PLY ,SINGLE 105 PSI ,DUAL 95 PSI.I run only 40PSI in the front .The rears are dual SAMPSON HI-WAY EXPRESS 8.25 X 20 10 PLY , 85 PSI SINGLE , 75 PSI DUAL .I run 35 psi on the rear duals.My truck only hauls me and the lower PSI makes the ride very comfortable.The tire shop also told me the lower pressure will help the tire last longer if you are not hauling a load !
