Time to mount the GPS antennas. No surprise here. Just drill holes and mount as planned on the plate I created on the firewall. Worked well.
I made an RG-400 cable for the Garmin antenna to run to the 430. But I was slightly confused what to do with the wires from the Dynon antenna. Turns out they run to a connector labled GPS. There are only 4 wires and I found the wire/pin map in the Advanced Installation manual.