Hi Garrett,
I've started using a bit more high tech solution. You can get dash mounted GPS speedometer (and does all kinds of other stuff) online for ~$50 dollars. Also they make GPS based in dash speedometers. And the one I use for stock in dash, and the most expensive one, is a GPS to speedo converter box.
With the latter, everything stays and looks the same but the box goes in the cab and then a short cable goes from the box to the speedo. Change tires, change settings...change wheels (and tires), change settings, change rear end, change settings.
I'm not sure what the rules are on posting links and specific products but the above mentioned is easy to search for.
