Wiring a fuel tank selector valve

I am trying to learn as much about switches as I can with regard to wiring in a 6 port (both supply and return) fuel tank selector valve that will also switch the fuel gauge sending wire connections
(such as a Pollak or Delco shown here:
http://www.oreillyauto.com/site/c/search/Fuel+Tank+Selector+Valve/02541/C0025.oap?keyword=fuel+selector+switch&year=1980&make=Chevrolet&model=C20+Pickup+RWD&vi=1032297 ).

Of course the 5 prong wire connector
(http://www.oreillyauto.com/site/c/detail/BWD0/FSV3A.oap?year=1980&make=Chevrolet&model=C20+Pickup+RWD&vi=1032297&evaritm=BWD+--+FSV3&rpl=1)
is additional cost, but wiring is straight forward with diagram
(http://products.pollakaftermarket.com/Asset/42-159 IS_41-revdd.pdf) .

The above examples are motorized valves as I understand, as opposed to some older style selectors that are solenoid activated valves with a single wire (such as this: http://www.amazon.com/ACDelco-467513-Fuel-Selector...)

Question: Is there an advantage to using one or the other (The solenoid style is harder to find and I think its out of production)? I think I understand the solenoid style uses a DPDT switch on the dash that has on positions that stay on (as opposed to a spring loaded 'momentary' on that then moves back to off when released). And I assume the sending unit wires would be wired directly to the DPDT switch terminals (properly of course)?

Also, with regard to the motorized valve - I understand it uses a DPDT switch, but would it be a standard stay on switch, or should it be a 'momentary' on? If the switch stayed on, could it burn out the motor on the valve? I like the idea that the dash switch stays in the on position just so that its easier to know which tank is currently being used but don't want to burn out the motor and the Pollak directions don't specify.

While I am here, I might as well throw out one more question but will also go to the FLAPS and see what they say: The delco 6 port/5prong motorized valve seems to come in two part numbers: u7000 and u7001. Is there any difference between these?

thanks

 

I believe the solenoid driven selector needs power to stay in one selected position (such as auxiliary), then turn the switch off and it would return to normal position (main tank). It looks like with the solenoid you would need a separate switch for the fuel gauge reading. It shows non fuel return solenoids available, do you definitely need the return? Does anyone know how much fuel actually returns? Would it be feasible for the fuel to always return to the main tank? To me the simple solenoid would be the lesser of 2 evils and probably more reliable. Definitely less to it. you could always put it where swapping fuel lines would be simple and then if it failed you wouldn't be stranded.

 

I think the solenoid valve can be operated with a single pole switch, but if a double pole switch is used then I can use the second pole for the sending units - but not 100% sure. My main thought with the solenoid is that it would be more reliable and it reportedly comes with 5/16 supply and 1/4 return nipples. The motorized Pollak unit generally comes with 3/8 and 5/16.

Thanks - their site does answer the question:
"Motorized valves are driven into position by an electric motor and are stable in either position. They only draw power for a fraction of a second during transfer. A switch in the valve shuts off the motor when the valve reaches the selected position. Note: Another switch within the valve provides automatic fuel gauge readout for selected tank"

 

My thought is to place the selector valve on the firewall in the engine bay behind the air cleaner. My current hard fuel lines in the engine bay end (or have been spliced into) right behind the carb - not sure if that was original or not but the PO was running an electric fuel pump (I currently run the mechanical) and that is where it was mounted with short rubber fuel hose connections. The fuel lines to the underseat tank are the black plastic nylon type which I also assume was put-in by the PO. I just ran hard line from my rear tank up along the passenger side frame rail and up the passenger side of the firewall. I will have all the line connections right there so seemed like a good spot and minimizes the amount of rubber fuel hose. In theory, if the valve fails I should be able to relatively easily access everything and bypass the valve if I have a little extra hose with me (which I carry).