For that fuel gauge issue...
I don't think you can splice the inputs together, it might make the gauge signal read at 1/2 scale.
You could add a balance tube and then use 1 gauge? Does your tank2 have the spare outlets?
Or add a second gauge and have 2.
Oh yeah, check out www.cpperformance.com (http://www.cpperformance.com) for a manual valve and they might even have an solenoid actuated one too.
[This message has been edited by MoJetBoPar (edited March 15, 2002).]