I can say it again, call BLP, or Braswell, or Book, or Cubic, or or or and they will tell you the same thing. They won't touch it.
Holley designed that carb for a NASCAR class back in the day. They were meant to be modified. Holley was behind the 8 ball in the industry so they marketed this pig and let the chips fall where they would. I got burned by it. Over the years I changed boosters, several times. It was best with a down leg. I made the air bleeds and emulsion changeable. That helped. I tuned and tuned and tuned. Always had a hole in the fuel curve. If you filled the hole it was pig rich. If you made it the correct A/F ratio it had a hole in the curve. I eventually bought BLP metering blocks and BLP baseplate. It helped. Finally, I was sick of screwing with junk and bought a BLP B4X and ended the torture.
Just because they keep selling it doesn't make it good. Junk is junk at any price.
I don't me to pee in your lunch but truth is truth and facts are facts.
If you can make it work, I'll send you my carb and you can fix that one too.