Hey Chevy,
I have a '56 4100. I found that '57 parts will work, you realize the hood is different, '57 has ribs, 55 and 56 do not. My truck, somewhat smaller than yours uses pick up doors and hood, fenters, bumper, grille unique. The only thing different when I put '57 fenders on my '56 were the bolt holes for the grille center section were slightly different. I just redrilled the holes to line up. If you got matching year parts, should be a piece of cake. Enjoy your truck!
P.S. The best thing I did to my truck was repowered it with a 350 and installed radial tires, made a huge difference!
