Holley, needle valve adjustments

I have a couple questions about adjusting the needle valves on my holley. I had it rebuild 3 years ago and haven't had any problem until now. To start, I was flooding from the rear or secondaries. The needle valve had junk in it, cleaned it out and put it back in. Where should the gas level be at in the plastic sight windows? It seems I can't get them set just right. After messing around with them yesterday. I have the the secondaries just below the window and my primaries are flooding. It seems I make small adjustments and I'm over correcting.
Should I be cracking the screw on top and turning the nut 1/4 or 1/8 turn then tightening the screw?

I have a couple questions about adjusting the needle valves on my holley. I had it rebuild 3 years ago and haven't had any problem until now. To start, I was flooding from the rear or secondaries. The needle valve had junk in it, cleaned it out and put it back in. Where should the gas level be at in the plastic sight windows? It seems I can't get them set just right. After messing around with them yesterday. I have the the secondaries just below the window and my primaries are flooding. It seems I make small adjustments and I'm over correcting.
Should I be cracking the screw on top and turning the nut 1/4 or 1/8 turn then tightening the screw?
Do you have a fuel filter? If you're getting crap in your needles and seats you can adjust them till the cows come home, but you're chasing your tail. To adjust, loosen the sloted screw, and turn the hex nut clockwise to lower, and counter-clockwise to raise your fuel level. I hate those sight plug deals. I unscrew them (or the stock plug) and get the level ro where the gas is just dribbling out the hole when I shake things around a little. Then down 1/4 turn. This helps keep fuel from sloshing out the breathers in rough water. When you're done, hold the hex nut from turning, and tighten the screw. Pretty simple.

I do have an in line fuel filter. I changed it when I saw the crap in the needle. It was from the orginal owner, so I have no idea of its age or condition. So the fuel should be below the window. I was trying to get it right in the middle. So I have to much gas in the bowls.
Thanks for your help.

I still have metal plugs in mine so I pull them and set till fuel just wants to come over the threads. I have never had slosh troubles but I also have the bowl vent tubes (horizontal ones) in my float bowls and center hung floats. At least I've never had slosh troubles I am aware of.