As mentioned before, I would just unplug and replug the connector on the VSS, just to make sure it was getting a good electrical connection.
I don't know that the other sensor is the same. If they do have the same numbers on them if legible, and they look identical in size and penetration to where the gearing is, then I guess it's a reasonable risk to swap them. It just doesn't make sense that VSS could be your problem, given the computers and ultimately speed control (which VSS feeds) works fine.
Hate to say it, but I think you should be looking at cluster #6