11-18-12 Part 2. After the front floor mod, I moved to the back end of the plane to install the OAT for the Dynon ADAHRS unit. I drilled a hole in the side of the fuse then opened the hole up to 3/8” with a unibit. Also drilled a ¼” hole in the rear bulkhead. Deburred both holes, then installed a rubber grommet in the bulkhead hole. I fed the wire thru the bulkhead grommet and installed the OAT in the side of the fuse. Thought I was done in the tunnel—Wrong! I will have another trip or two to secure the probe wire and plug it into the ADAHRS unit.