Image 1 shows again how I back drill through 1/8” scrap to get holes where I want them. The caliper is actually serving as a clamp as well as proper dimension positioning.
Image 2 shows one of the visual clues that the tunnel is in proper position for and aft. Notice the consistent dimension between the vertical tunnel and firewall.
Image 3 shows the holes in the firewall recess backed drilled through the tunnel. I’ll platenut the firewall recess now.
