I stopped at AirFasco, Inc. in Canton. They make AN hardware and provide inventory to Van's. I picked up six different bolts sizes. I used two bolts to attach the fuel flow pressure transducer to the bracket.
Two 1/4" ID tubes were cut and placed over the bolts for the ammeter shunt to provide more support for attaching the ammeter shunt to the firewall. The cockpit side should have a doubler applied over the bolts.