RE: Patriot related
you connect the fuel feed to the needle to a Tee - and the muffler pressures to a Tee fitting.
Both are in parallel... one does not feed the other. No difference which one empties first.
But no, it will not function like a header tank does. On the patriot, you will not really need the header tank if you use a bubble tank, and move the tank aft.
Look at central hobbies' website. Some of the Tetra bubble tanks may fit the available space a bit better.
Yes, the engine mounts are pre-drilled and tapped for the engines. Simply specify the engine.