The Flathead starts instantly and purrs.At idle there is a bit of air on top of the gas in the glass bowl.When I increase the rpm more air and it looks like boiling water.
I tightened up the hoseclamps etc and it does not boil like water anymore,but still there is a bit of air on top in the bowl.Underload it runs a bit better,but not much.
I have not replaced the gasket on top of the glass bowl. I'll do that today.

If anyone has any words of wisdom,thanks in advance.

Cheers

 

Do the above as a start. Then check all soft lines to the tank. No, better yet, check all lines to the tank, you could have a pin hole in any of the line. This is always a good thing to do with an unknown vehicle.
Then check the output of the pump if you're still having problems. How does it run under heavy load? Or are you just concern about the bubbles?

 

If I understand you correctly you should know that air on top of the gas in the carb float bowl is normal. So is some turbulence as you use more gas and more fuel is added to the bowl. See the following video to see how it should look (https://www.ford-trucks.com/forums/1170569-about-to-throw-in-the-towel.html#post12168774).

You need to give us a description of the engine operation problem. Does it stumble as you open the throttle or what? Also note the level of the fuel in the bowl in Ilya's video. If your float level is set too high that will cause problems.