You ought to check out
this Tech Tip on Spotting Art Deco trucks.
There is a whole
section in Tech Tips about identifying your truck. One specifically about
deciphering your VIN. As 3B suggested, take a look at
the Links Page. There is a good breakdown on the first page of categories. Subsequent pages have links listed to suppliers. Almost 1,000 listed.
And as 3B said, American Classic Truck Parts (see the link in the left hand corner) and Jim Carter have been enthusiastic
supporters of this site and the restoration hobby. Both offer a 10% discount to members of our group (need to ask for it). Jim Carter is a real truck nut -- you can even call him to ask questions. He's offered help many times on our site, especially checking over Tech Tips (like the Art Deco one - he gave it a glance and sent in some changes for us). All around good guy.
Good luck.
Peg