Any clue as to what the A1 at the end of the serial # is? Engine appears to be original truck engine with solids.
A1? Maybe someone else knows or can give a good guess?
What characteristics does the engine have to indicate that it is the original truck engine?
You must have taken out a lifter to confirm that it is mechanical?
What is the block date-casting code and what is the block casting code?
You could have a later block that was a factory replacement, or you could have an engine out of another vehicle (used as a replacement)?
The engine ID could have been "doctored" over the years.
