That would work but $1500 is not in the budget for just fuel selector valves.

Even if you return the fuel to the filter heads instead of the tank, you will still need 2 3 port valves to switch between the saddle tanks and the main tank. I doubt that there is that much difference between the cost of the 3 port and the 6 port valves. The only other option that I can see is to T all of the tanks together with valves on the saddle tanks so that you can gravity feed them into the main tank, or put a fuel pump on the saddle tanks and pump them into the main tank. I am personally not very keen on either of those options. I would end up forgetting to close the valves or shut off the pumps and overfill the main tank. I would do it correctly the first time and be done with it. One switch on the dash will work both valves and they will also switch the fuel gauge if you only have 1.

I thought coast guard regulations didn't allow you to return gasoline back to the tank. That is why Mercury returns back to the filter head. I could be totally wrong too.

MOst of the ski/wake boats not just return back to the tank but have the pump in the tank like vehicles.

There is no mention of a return line in the USCG fuel system standards, it just states what material the lines should be made of. This is old info from a boat builders handbook from when I worked at Celebrity boats though.

Thanks guys