Gas help!

[Security guy]

No, not that kind of gas! I finally got my carb issues figured out, but I'm having problems with getting gas to the carb. Its a 402 with a fuel pump from an earlier car. The pump only has two lines, one in and one out. It ran great with another carb, but the other carb was running to rich. I put a little smaller quadrajet on it and it runs great on take-off. The problem is at 55-65 mph. It starts cutting out and almost dies. If I stop, it fills up with gas again and I can go another mile or two. I have a clear fuel filter just before the carb (not a glass one) and I can see the fuel coming in the filter. It works great when the engine is cold. After the engine gets hot, the fuel just barely dribbles in the fuel filter which is probably why the carb is starving for fuel. What is causing this? I thought vapor lock, but I've heard that is very rare with todays fuels. Is the pump going bad after it gets hot? Its a stock pump from advance auto parts. I think the feed line is clear because when its cold, it gets plenty of fuel. It just seems to do it when the engine is warm or hot (140-195 degrees). Any thoughts? Just replace the fuel pump?