Tracking down a low fuel flow issue, it looks like it starts with the flow directly from the tank. Sure, it's a small steel line, but the flow is very little. If the pump is not receiving enough, how can it push anything back to the engine. Drawing a blank

carbs, pump in front

Clogged filter sock in tank most likely based on what you’ve posted.

The other possibility is kinked fuel line coming out of the tank.

Least likely but not impossible is that the tank isn’t venting. Pop the fuel cap - if flow improves it’s venting.

Looking through the filler inlet I can see the sock looks reasonable. Will pull the tank later to look for a kink.

The number of options for this is very low

Are you checking at the metal pipe coming out of the tank, or a rubber line attached to it? If rubber line, it may be swollen.
If the metal pipe, carefully push a a piece of copper (soft) wire into the hose and tank. It should go in a good 3-4 inches. Just be ready if it clears out something, you will get all the fuel flow you ever wanted...

If that doesn't do it, then probably time to pull the tank. If I recall, getting that pipe off while in the car is not easy. Maybe drain the tank using a siphon pump.

You can see the fuel lines from under the car (and if you have a door covering the front fuel pump area, you can check the lines there too) without removing the tank. Good luck with the fix!

I am not running a return line, so one of the lines on the bottom of the tank is plugged up. I had my feed line on the wrong one, switched them and now the sock is doing it's job and the flow is much better

It's usually the simple things...

That sock is a useless item, much better to install an external filter right out of the tank before the pump which can then be visually checked and easily replaced.

Yes, I always install a filter as soon as the fuel exits the tank and another in the engine bay before the carbs