[GreyGhost702]

You might get better feedback in the tech section of the forum.

Might need some more context for this, as well. Why the need for a regulator on the low side? So you went dual in-tank pumps, looks like upgraded line. Are you doing a return style fuel system? If not, there shouldn't be a need for a regulator in a returnless system. The regulator will cause the computer to fight it, because the computer controls the pumps. It spins the pumps via voltage controller, which controls low-side pressure as commanded. This may be why the gauge is showing erratic readings, it's trying to fight the regulator for pressure control.

Again, just need more info on what is going on here. easttxss is also correct, for the boost reference port. Though, the port would likely see vacuum depending on the sample source, I don't think it would hurt either way to hook it up. That gauge, however, is only sampling what's happening in the valve body, the gauge won't see vacuum or boost, only the pressure in the fuel line. If the needle is flying, so is your fuel pressure most likely.