It's a compound angle to get the flange flat and straight along the centerline of the opening in the firewall and the top of the quadrant. I made a wood block with the right angle. Drilling the 1/4" pilot was no problem. I drilled the hole on the wrong side of the centerline to get the hole centered across the full width of the plates. It turned out okay but it galls me that it wasn't perfect.

Owner caption February 2014 · Photo 90 of 429