Hey pals, maybe this is an easy one that you can help with.
Trying to get the car ready for the trip to So Cal. The Charger runs fine but the fuel pressure reading is confusing me. When the car is cold and first started, the guage on the dual feed line reads a solid 7 lbs at idle. The clear filter is full and things all seem good. Once the engine warms up, the fuel pressure goes down. This has happened in the past, noteably during camshaft break in where the engine began to stumble. Once the pressure drops, the fuel filter also shows it: Fuel no longer fills it completely, it sometimes just pulses and bubbles in there. The pressure drops to zero sometimes.

The engine is a 440/493, MP 528 cam, 2" headers, 3" exhaust, Holley mechanical pump with less than 2500 miles on it. I have the A/F tuned with a wideband guage. ALL fuel line connections are secure. Gas tank and sender was new in 2003. The car runs fine when cruising but will stumble sometimes at WOT. I had a Carter pump on it once but it read 11 lbs at idle. I figured I'd try it sometime later when I had the time to integrate a regulator and a return line. I didn't have the Carter pump on the car long enough to see how it was with the car in use.

I don't know if this could be considered vaopr lock. The car runs a consistent 200 degrees. This happened before with another Holley pump but I didn't want to bash the brand. I'm probably going to try the Carter pump again just to see what happens with the engine up to temp.

Any suggestions on a decent adjustable fuel regulator with a return port? I don't know much about these setups but I was planning on using the 1/4" vent line for the return line. The fuel line is a 3/8". The 70 Charger has the 2 nipples on the fuel sender as well as 5 hoses that come off of the top of the tank, routed to an evap tube mounted to the RH side of the trunk floor near the wheel tub.