I had a 3/8 tube with a rubber hose on the end of it with a mess screen I made a 1/2 stainless steel pick up with a stainless 1/2 npt fitting for my 5/8 line. before I changed the whole system it was 3/8 and i was running out of fuel @half throttle and would run right out @ wot.... I could see it going on and the hole time I had 7 psi... but not a enough volume I have like 1/2 sights in my fuel blows and I can read my exhaust temps and afr too. I never let it run below the sight glass on the blows.

GG,
If your FP is 7 lbs at WOT, I can not see how you have fuel supply issue.

It's not all about fuel pressure it's more about the volume.... you can have the pressure in the fuel system but if cant fill the blows fast enough whats going to happen you will run out of fuel and then you will see the fuel pressure problem too in the end.the pressure that you see and read is the pressure from the pump to the needle and seat not the fuel blow pressure and that is where the problem comes to play not able to keep the blows filled.

If you are measureing FP at the fuel rail or carb, the FP will drop if the bowls are not full.

Look you can have all the pressure you want... If you do not have the volume you will not fill the blows fast enough your pressure drop is in the blows. plain and simple.... not the lines they will make it look like you have good pressure because it can keep the lines filled for the most part the needle opens so fast that a dial gauge will not see it more so if it is a filled gauge.

tt

Are the bowls on the carb in the pics the proper size? They look a bit small....maybe its just the air cleaner that makes them look small.

They look like they are from a 600 or 650 they do look small. but I think they are right. I just went to the holley web site and the look the same.

I'm running a 850 Barry Grant and the blows are way bigger than those.

I run an 850 B.G. Mighty Demon and I was pretty sure that mine were considerably larger.

Right that's the way mine is too.