Fuel pressure dropping while driving and under acceleration to zero at idle runs 4 lb electric Blue

On the last pic it shows the regulator. The Holly regulator underneath is all gutted completely out. It's just a t to supply both of my carburetors on the front hose going to front carburetor. There's a gauge then on the back hose going to the other carburetor is a gauge going to the one mounted on a plate behind the air cleaner and I took out the brass plug and put a gauge there and they all read the same. But I will get a few fittings for the incoming side of the regulator and put a gauge there