Re: Vapor lock or something else?
I might have to disagree with you on the fuel filter being full. I haven't checked it while the engine is running but I have a pick up with the same engine, carb, pump and filter, also 2 trucks with small blocks same carb and filter. They all have the exact same filter and I just popped the hoods, they're all about half full, I've never seen them completely full and I've had one truck since 1999. They all run perfectly fine, 2 of them have new pumps and filters. Maybe it's the style filter or maybe you mean when the engines running but never seen them full.
67 454 Edelbrock air cleaner, performer carb, intake, heads & shocks. headers to 3" duals, HID 85K headlights, custom motorcycle twist throttle controls (paralyzed waist down), all new interior