Yeah, like within a quarter year of production or so. Not like "between 1970 and 1973"
Reason I'm asking...building a '72 340 that came with a cast, externally balanced crank. I'm replacing it with a forged, internally balanced '69 340 crank. I need to buy a new damper that will fit the forged crank and need to know which timing cover, water pump and radiator to use.