I have a 502 w/carb that stalls after about 30 min of driving. It kicks like a bronco then dies. I didn’t know why at first. It would restart after a few minutes of sitting. My mechanic thought it was vapor lock so we added a phenolic spacer between the carb and intake. No fix. He then saw some fuel pressure fluctuations so he replaced the regulator and added another fuel line to the rear bowls. No fix. The next stall, we noticed it was flooded. We drove it with the air filter off and while looking through the cowl noticed that when it "stalls" it spews tons of fuel out of the carb vent tubes. We now think it is either starved or getting air. So we are debating on a fuel bypass/new pump vs. a new fuel system (Aeromotive) to include a new tank with internal pump. Both should solve the possible air issues and potential starving. Should I add the bypass to my current system and replace the pump? Should I go with this Aeromotive system? Price doesn’t seem to be too different, but I am getting tired of going round and round with this problem. It is too much money in the engine for this kind of crap. Need help! Thanks.

if fuel is coming out of vents there is a problem with float or needle and seat

On the second fix, we replaced the needle and seats.