Dan,
What is your code?
The code formats and meanings are different for different years of trucks.
Here is code information for 1939 Chevrolet vehicles (cars & trucks). Depending on the year of your engine, 255 might mean the engine is a 1955 second series truck engine (from a 1955 Task Force truck).
Here are locations of various identification codes. Post your codes here and people will help you ID the engine.
It is quite common for a truck to have a later replacement engine. This makes it interesting/difficult/frustrating when the title/registration used/uses the original engine as an ID.
