Have a Hangar 9 Areti 40 with a Saito 72 up front inverted.

Regarding engine tank location, can I mount the tank right at the exit hole in the firewall or should the tank be physically lower than that? Also, should the tank be inverted or right side up with respect to the engine??????????????

As well, can you tell me the best CG location for this plane???

Glowfuel