Holley/Demon Carb stumble

((I did not read the first 17 pages, so take this as you may))

9psi is a lot, I would back that off to 5-7psi to prevent pushing past the needle valve.

Spring on float...make sure the float moves freely up and down with no hangups. I had a down track issue about 6-7 years ago that was nothing more than my rear float sticking, the needle not shutting and flooding the crap out of my carb (fuel coming out the vent tubes).