The extra wires are a plus as long as there are 3 extra wires in wall. You need either 5 or 6 wires between the thermostat and the A/C control box.
Now comes the other shoe. You will also have to change out the control box from the current digital communication model to an analog model in the A/C. It's not a lot of work, it's just a little bit of additional expense. Dyers is a good source for getting you what you need to do the swapout.
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!