How to tell what a 360 originally came from ?

Hi it was my question everywhere i go everything jus pops up for the car vin but cant find anything on what the numbers on the block mean i have decoded the date i know its a 1973 block but i found a number down on the back of the motor and it looked like 3m360R4471 the casting # 3418496-4-360 and another question on the crank the #3418640-2 what is the (2) mean