Do you realise that if you run that new 14 with an old chain you are tempting providence.
The old chain will quickly wear the new 14 out.
I have experienced times that an old chain has broken trying to accomodate the pitch of the new sprocket.
Sprockets and chains should be kept as matching sets.
I'm getting a new chain, as well as a new rear sprocket, the old chain was horrible, and i would never mix up old and new, i'm replacing it all at once.