'50- '54 "Cannonballs" had the Bumper Bar grille, as the other GMC trucks used. My '50 "Cannonball" was this way. The '55-'59 "Cannonballs", had a flat grille, like this one does. Also my "Cannonball" was all steel, with a rounded back of cab. The '55-'59's had the flat, back of cab. I found a '56 model "Cannonball" single axle diesel tractor, near work, several years ago.Trying to talk the owner, who is a fellow ATHS member, into selling it to me. Better get this truck. You'll wish you had, if you don't.