sent this to John via PM but i'll post it publically now that things work
first thing that would come to mind is the hood emblem differences, 55.2 has a very unique emblem not shared with any other years and has the eggcrate style grille with it consisting of three horizontal bars and 3 vertical bars, '56 is identical exept for the emblem is longer on the bottom and the fender emblems are two piece. '57 has the same hood emblem only the paint scheme is reversed (black bowtie red around bowtie) and has a new grille and oval fender emblems with red paint, series designations are 3,4,5,6 thousand with these being the most encountered but there also are 7,8,9 and 10 thousand series trucks, I'll let Grigg or somebody that has one of these go ahead and tell about them. also the bigger trucks have the ledgendary "Buckteeth" that inspired the character and my hero Tow Mater
