A trick I've used on boat instruments is to clamp the existing panel onto a sheet of plywood, find the center of the hole and use a hole saw to make the cut. The pilot hole of the saw- the drill bit- just bores into the plywood while the saw cuts the larger diameter hole in the panel.
If you have a pre cut dash, FFR has CNC'd preferations (sp?) around the tach and speedo holes to be enlargened to accept bigger dia. speedo and tach. Simply break off at the preferations to enlargen the holes. Your tach and speedo may fit loosely in the holes, but will be tightened when you cover the dash with the vinyl padded dash cover.
A forum community dedicated to Factory Five owners and enthusiasts. Come join the discussion about performance, racing, conversions, modifications, troubleshooting and drivetrain. We discuss MK4, GTM, 818, Type 65 coupe, roadsters, and more!