I'm moving your question to new post so it doesn't get mixed up in who did what and the answers in that other post.
The Baldwin filters (BF825 ?) should be fine. You answered one question, you have the filters with the holes in the top, not the Wix, NAPA type with the groove a gasket can get into. There should be only one seal in the grooves of the filter housing to seal the top rim of each filter element.by 450FiveString » Thu Apr 18, 2019 12:30 pm
I just changed the filters in my straight 450 and have exactly the same problem. The filters I took off had no markings so I don't know the brand. I put Baldwin filters on and they have holes in the top just like those I took off. I've got fuel coming out of the mechanical pump and the line is clear to the filter housing. Filter #1 fills the glass bowl partially but nothing comes out of the bleeder. When I took off the original filters there were 2 seals on top. It appears that the one in the housing groove was never removed.
The fuel flows in the side to the center of the first filter (the one with the glass bowl). It goes up through the filter and across to the second filter and down the center of it. It goes up through that filter and exits at the top where it goes to the injection pump.
Did you change the filters as part of a normal service or was it because of an issue you felt was fuel related? I assume you are using the primer lever to fill the filters. If it is not getting much stroke you may want to try bumping the engine a bit to get a better stroke. How much have you pumped it? Sometimes it takes quite a bit. Do you have the bleeder screws open on both filters? You might want to take them out and make sure the slot in them is not plugged. Some basics as a starting point.
Jim