I could not find anywhere for it to go looking through the Corsica manual not did I see it.
If it is a pump out of another car, be carefule as pressures can be different and cause problems.
The only thing that you can be sure ot is that, and it says this in the manual, you want evry opening plugged.
So, get some adhesive silicone and a proper rubber cap to seal the hole. You could also put adhesive in the tube and drive a screw in it that fits.
I can't think of any vacuum size lines in general excpet the balance line that goes between the tie rod end boots on the steering rack itself.
Let me knwo if you need any further help with this issue.