Adding a tach

[Baby John]

Is it possible to add a tachometer to my standard guage cluster? Or do I have to replace the entire cluster?

I really don't want to do that since all my guages work fine including the lights and turn signal indicators.

Also, I'd want the factory look...not an aftermarket guage, unless there are aftermarket guages that are replicas of the original.

Also....what's the empty guage to the right of the steering column @ the bottom of the cluster? Tranny old temp?