I'm hoping someone out there can help me with this.

I have a 69 Suburban with a close to stock 396, Holley 670 Truck Avenger carb and Holley red electric fuel pump plumbed in 3/8 line. When I start it cold I have 5-6 lbs of pressure at the carb but as it heats up it drops all the way down to 0, but maintains idle and even seems to drive OK. It just won't tow without bogging. I put a different gauge in just after the pump, which is mounted about halfway up the framerail, and it stays at 5-6 lbs. I thought the fuel line in the engine compartment was getting too hot but I can still feel them with my bare hand and they don't seem that hot. I put a return regulator and line in to get more circulation but that didn't fix it. Iv'e tried running just the pump without the engine running and noticed no drop in the same time frame. I replaced the 3' of braided line feeding the carb in the engine compartment with steel line and made sure it was not in direct contact with anything and no change.

I thought that the fuel pressure problem could be causing a lean condition and that is what is causing it to run hot and eventually overheat

I'm almost certain that fuel pressure at the carb is not suppose to drop to nothing even if the bowls are full, so what gives.

I've been working on this thing for years and any help would be greatly appriciated