Just a heads up for anyone considering a build or changing the gauges
The RCR dash is molded to use their Speedhut gauges. 2-1/6" small gauges and 3-3/8" Speedo and Tach.
When you drill out the small hole, the outer diameter of the gauge is larger than the land that is left on the fiberglass. If you're anal - it will take some work to provide a flat land for the gauge.
If you are using Smiths gauges, their Speedo and Tach are 100mm (3-15/16" almost 4") The Speedhut is 5/8" smaller. You will have to do major remodel work to fit the larger Smiths gauge in.
FYI
Paul