I have a number from the top of my drivers door opening "C1546S124561" tried Vin buster it only comes back as a missouri suburban with no other info.am at a lost as to next step.the truck was traded to me as a 66 gmc but i am not sure now the previous owner said it may be a 64 chevy.its a nice truck and i have put a great deal of work in it now i just wish i knew what it was?any help would be greatly appreciated.gofastdaddy and his mystery truck.lol