My 9" does the same thing. Always has. The 8 3/4 in my buddies rail does it too.Maybe because they are narrowed so much? I dont know.
We took the vents out,screwed in a pipe fitting with a 5/16 barb fitting and a piece of fuel line up to a el-cheapo fuel filter tied up high on the frame. Not pretty but it works.
If you find a good solution I would love to hear it since I am putting that car back on the highway soon. Thanks