The VA-168 transducer manifold is bolted to the firewall using two AN3-5A bolts through both the firewall and the F-745-L top skin rib. The top hole is existing and is located 3rd hole from the top of the firewall. I enlarged this hole to #12. Next, I bolted the transducer to the firewall and used the lower hole on the tranducer to match drill through the firewall and rib to #12. I deburred the holes and ordered the hardware.
