Finally got my gauge holes cut. 54mm holes for the smaller gauges, no problems as I has a hole saw for the job. The 2 bigger gauges needed 86mm holes. I only had a 76mm or 90mm. I had to use the 74mm. The routing to extend the diameter of the hole was done with a flap bit. Just take your time. Go slow and work in circles, apply even pressure to all sides of the circle. Check if the gauge fits evey 1 or 2 revolutions, so that you don't route it out too far. If you don't know what I mean, let me know and I'll explain it too you. Anyway, I'm happy with the result and on a WHITE GLOSSY 2pac paint these gauges will look superb.