Fuel Pressure drop in traffic ???

Yes it Is. My 680 Quick Fuel Carb is Supposed To Stay At 6 1/2 psi. But I Know volume is the big key as long a pressure stays above 5 psi. Thinking of going all 1/2 in. and #8 lines front to back.

Glad I asked, most likely just your gauge. Read up
http://aeromotiveinc.com/fuel-pressure-gauges-liquid-filled-vs-dry-problem-solution/