[Singleton]

Originally Posted by jhein

I don't know but people have suggested that even if I don't have any obvious starvation, it's still happening. I don't know if that only matters for someone who is racing or if would have any noticeable effect in a street only car like mine.

My GTO, (in signature), had the 550 RobbMc mechanical pump for several years with no noticeable fuel supply issues. Also used the RobbMc 1/2" tank pick-up along with 1/2" lines.
About two years ago. frustrated with the same issue you're describing with the empty fuel bowls, I decided to ditch the mechanical pump and went with the Tanks Inc setup with the in-tank 450lph pump and 1/2" supply and return. Used a cheap quickfuel bypass regulator plumbed-in after the carb, no hobbs switch.

I didn't expect any performance gains, since the car ran really strong on the street with the M&H drag radials, 495cid, 4sp, 4.10 gears. But after the electric pump install I was shocked at how quicker the engine pulled to redline. Like I said before, it ran great on the mechanical pump, but there was a noticeable difference after the Tanks Inc set up.
So the dry fuel bowl issue is solved and a slight fuel starvation issue that I didn't know about is also solved. And if I decide to go EFI, most of the components are already in place