The engine/head numbers you are giving us are called "Casting Numbers", these are not the stamped engine code/serial numbers. There is a flat machined surface to the rear of the distributor that will have the engine code and serial number. You may need to scrap the paint off to see the numbers.
The CON 2 is the conveyor that the engine was cast on and the K64 is the date code with K = month, 6 = day and 4 being the year (1954 or 1964). Without the engine casting number found on the front passenger side of the block down near the oil pan we can't say for sure what the engine is. So far you only know what the head is...
Did you confirm the title serial number is the same as what's on the truck?
Mike B
