You will not find a serial number anywhere but on the engine, right by the distributor. If the original engine is missing, you have no VIN. The cab tags contain other information. It wasn't till 1955 or so that the VIN was stamped in frames.
You will need to get with the DMV and see what is needed for your state.
Your old title would not have been any good if the engine was changed or going to be changed, so don't worry about loosing it to much.
Joe
