My 97 F150 odometer quit working. Speedo works fine.

I found another gage cluster at a salvage yard, but Chiltons says it has to be reflashed at a dealer when changed.

Is this the case, or will it work ok, just show the mileage that's on it?

It has the old fashioned looking mechanical display, but I did not see a place for a speedometer cable to connect.

Any help is appreciated.