I like to complete the setup of the engine mount, fuel tank and nose gear steering before the firewall is installed. It is a lot easer to drill holes and mount stuff with the firewall on the bench. Many years of building Howard Engineering kits has influenced the way I build, so I’ll be borrowing his well engineered fuel tank mounting system for the Cold Duck. See my Howard Engineering Kwik Fli III build on RCU at
http://www.rcuniverse.com/forum/m_2434444/tm.htm
A plywood plate is made for the front of the fuel tank that bolts to the firewall with blind nuts. It is a really neat system and keeps the fuel lines from getting kinked and makes tank installation and removal easy. I’m using the specified Sullivan RST-12 fuel tank.
I decided to mount the engine less than the original 90 degrees for a little more muffler clearance.