[Formulajones]

I check it running.

Original Holley bowls had the front bowl sight screw higher than the rear bowl sight screw. Many don't realize that.
Aftermarket stuff I haven't seen that. Just an fyi. The level will change the AFR slightly, but not a crazy amount like you're seeing.

I initially set them with the bowls off the carb. Flip it upside down and look at the float. Turn the adjustment nut until the float is nice and level. Done.
Can be tweaked from there after it's running but I don't always find a need to