I have a 91 ed6 hatch and I want to swap my cluster with a cluster that has a tach. Would I be able to swap it with an si cluster or a dx cluster? And if so would there be anything that I would have to wire up for it to work?

 

90-91 clusters should all swap without modification. 88-89 were slightly different and will require repinning- Google holds the answers.

 

I have a 91 Wagon cluster with tach, should be plug and play for you car.