No Gas to the Carb When Engine Warms Up

I have a stalling problem. I found the problem but I don't know why. I have a 70, 225, with a Holley 1920. I've read many threads on this subject and subitted one myself. I got a lot of great advice. When the engine is cold, the filter (clear plastic) is 3/4 full. After letting the engine idle with the hood open, for 15 min, outside temp about 75 degrees, the level of the fuel in the filter, goes to almost zero. The temp guage is on the first mark. The gas cap is off. I tried to put a foil pan between the engine and the filter. The filter is relatively cool but the gas lines are warm. I'm new to slant six's but not to MOPARs. I had a 340 Cuda with headers and have never had a problem like this. Do I need to insulate the gas lines and get a metal filter? The fuel pump is new and I just adjusted the float level. Is is common to slant six's? Thanks everyone in advance.