Just throwing this out there, I realize alot of people go these types of routes just for fun. You can get a cheap obd2 Bluetooth adapter that can pair with your phone, head unit, or anything else with Bluetooth and a display for less than what you're going to pay in boards and lose in time. I ended up getting one for both of my cars and it live streams almost all data as im driving to my head unit which has a custom dash app on it. It displays speed, temps, tach, voltage, and allot of other stuff like fuel to air ratio, vaccuum, what all light are in and trouble codes. I think its an ELM227 or 223 adapter, you can get the apps free or even get an lcd roughly the size of your instrument panel and completely replace it with whatever digitals you want.