What is the difference between a 350 and a 327?

How can I identify if my engine is a 350 or 327?

Engine block casting # 3970010

Vin stamped code 18l611487

thnaks,

Julio Zamago

3970010 shows up on both 1968 327's and 1969-79 350's

could be either originally.

without disassembly no way to really know for sure.