i think they should be joined somewhere to allow flow and pressure balance. just as out intakes have a balance bar. Also this would require two fuel pressure regulators. these regulators would have to be in synic. any difference would have to be balance by a balance line that connects the two fuel feeds. You would not want one bank having more or less pressure or flow than the other. Theres no garranty that two new pumps, regulators, etc will provide the exact same flow and pressure under the exact same loads.
seems pointless though when you could just join them at the back by the tank. run it though the stock hard line and do what ever people do with 300degree fuel fails.
i discussed this with someone in person before. he was pretty much crazy, and i told him there would have to be a balance line for safety and equalization.
