can you put the vacuum advance on the left side of the motor

You can move it over as long as you get the timing correct. Before you do anything note which spark plug the rotor points to. Once you rotate the dist. make sure the rotor is pointing to the same spark plug wire. You will need to fine tune the timing with a timing light once you get it running.

If the timing is just a bit off you could rotate the spark plug wires one place to the right or left to get the timing close enough to adjust by rotating the distributor.