I have been struggling with the same drip/flooding problem. I have three carbs and have what I think is the best of my Rochester Bs on the truck right now. I have tried adjusting the float level down to the point that there is no flooding. However this leaned it out too much and it didn't run right. What it proved to me is that given enough force, the needle and seat will work. The needle and seat are new from a rebuild kit.
Anyhow I got reading my GM Carb servicing manual for 1952 and discovered that they had made two different needle and seat combinations. The ones for the 216 had a .76" orifice and the ones for the 235 had a .90" orifice. I reasoned that maybe the floats in the 235 model were larger and could supply more force to the needle. So I found a proper 216 needle and seat in one of my other carbs and I installed that. The float is set to spec and it doesn't flood at all. It also rune like a sewing machine.
I am thinking that it requires less force to shut off the .76 feed that the .90 feed. I am looking at this from a hydraulic pressure point of view.
Another side issue is that some of the older carbs had a ball in the bottom of the pump well and some didn't. None of the kits I had mentioned that ball at all.
