Holley instructions contradicting on fuel bowl level ??
You got it.
Look at the drawing on page 4 above for the effect. But I think you got it,
pressure x area = force to keep the valve shut.
.110" diameter
7 lb/sq in x 3.14 x .55 x.55 = 6.6 lbs force
.120" diameter
7 lbs/sq in x 3.14 x .6 X .6 =7.9 lbs force