Fuel Pressure drop in traffic ???

Thank You All . I have 2 month old carter mechanical, 110 gph. pump,All New 3/8 aluminum hard lines, except at connections, new 3/8 fuel injection rated rubber hose. Do Have push connect 3/8 fittings at pump . The tank Only has one line ,the feed line, the vent on the filler neck would be my only possibility ???? Plenty of volume in 10 seconds, more than a pint. I Have a Russells Big Filter at the tank n a polished Fuel Injection filter just before the Dual feed line at the carb. Both rated at 90 to 110 gph.

There was a post here recently where someone had the same problem and it ended up being the gauge and not the fuel system dropping off, so maybe...