Rather than use the aluminum heater box that would melt in a heart beat should an engine fire occur, I decided on this all steel unit from Aircraft Spruce. Not much to say except it is a sturdy installation and a high quality product.
I decided to mount the GPS antennas under the cowling. Since the RV-8 has no room available on the turtle deck, you have to be imaginative to mount antennas. Many have mounted the GPS antennas under the cowling and although there is a potential for problems due to engine heat, I felt it was the least evil of all of the alternatives. Time will tell!