All '60 intakes were aluminum and undrilled. All '61 intakes were cast iron and drilled. This will not be an issue unless someone has swapped an aluminum '60 intake onto the '61 car.
Not quite that straightforward. The '61+ carb mount pad was enlarged to provide room for the PCV port to be drilled. If you try to drill this hole in the correct location on the un-enlarged '60 carb mount pad, you stand an excellent chance of creating a big ol' vacuum leak. There is a way around this that isn't terribly difficult, but requires some careful work with appropriate tools. But none of this matters when we're dealing with a '61 intake.
