While dead locked in the fuel sensor mounting issue (it should not be this hard...), proceeded with the installation of the cabin heat bypass on the firewall. Located the recommended position of the 2" diameter hole for the heater bypass per Van's plans. There are two recommended locations, one for the O-360, another for IO-360. The IO location seems to work best for me. Located the center of the 2" diameter hole to be cut, and drilled a pilot hole with #40. Enlarged the hole to the same size as my 2" hole cutter center bit, then used the 2" hole cutter to final cut the hole through the firewall.
Located the bypass to determine the general location of the holes required for the AN3 bolts securing the bypass to the firewall. Since the bypass already has the nutplate installed, exact location is difficult to determine.
Decided to make a template for the firewall to determine exactly where to drill the holes for the AN3 bolts.
