'71 with an LBZ duramax. Need advice on fuel tank.

[01chevduramax]

Hey guys I asked this question in the general forum. Didn't get much action.
I've got the duramax swap pretty close. I'm working on the fuel system. I have a plan, but I'm wanting to hear some feedback on it.

I want to keep the stock tank, and filler. I will tig a 1" bung into the bottom passenger side of the stock tank. Stainless elbow, to brass ball valve. Stainless elbow pointing back towards the drivers side. Stainless nipple across the front of the tank. Adapt to -16AN braided hose. Use a bulkhead 90 fitting through the cab floor. Short hose to -16AN tee under the cab.

From that Tee forward reduce to -8AN to fuel filter/lift pump then to the CP3 straight shot no test port.

Other side of that Tee: short -16 hose to bottom of a 15 gallon fuel cell mounted under the passenger side of the bed.

That fuel cell would get a 1/2" vent line out the top that tees into the filler neck vent on the stock tank.

My thoughts here are: the bottom tank would fill up as I pump gas into the top tank. Then the top tank would fill. Maybe a slow fill??

I'd use the stock fuel tanks sender. Probably put a 0-90 ohm sender for the fuel cell. Hook up a switch to watch top or bottom.

Anyone have any input? Concerns? Advice?
My plumber buddy suggested a brass ball valve to help with dissimilar metals. He got pretty scientific with it. I got lost! Help a brother out!!