Loss Of Fuel Pressure

We were out driving the Duster last night to a local car meet and noticed that when the engine gets warmed up we lose fuel pressure. The engine only has 260 miles on it. Let me tell you what we have and maybe you guys can tell me whats up. 360 engine , roughly 400 hp ,holley fuel pump 5/16 fuel line coming from tank,3/8 fuel hose from pump to carb. The reason I know that we are losing fuel pressure is that the engine will stall out at idle and we also have a clear fuel filter ,You can see the fuel just sputtering into the filter. It runs fine when engine is cool only happens after warm. WHATS UP ???

Thanks BOB/ BRYCE