E85 needs to 30% more fuel volume mate, remeber when this is done the car will be running 4 x 1000cc/min injectors, potentially with two stage injection later on (350cc/min primaries and the 1000's as secondaries).
Return will go back to the surge tank and overflow from that back into the stock tank. The surge tank should never be empty! (I can work out the mass flow rates, but I CBF'd at the moment)
I will probably run 1 044 to start, but i'll be fabricating the surge tank, mounts and plumbing to run 2.