I use a Weber kettle lid with the four holes that are about 1/2 inch. It works fine. For intake I have four 1/2 pipe nipples. Three have caps and one has a ball valve. Usually, I only need one of the caps off and the ball valve open about 1/2 the way to get it to chug along at 220-230.
I know Keale had some problems with too much exhaust opening. He had to stick foil in some of openings.
[SIZE="2"][FONT="Comic Sans MS"]Food! It's the second most important thing to a young man, and the most important to an old one.[/FONT][/SIZE]
Smokin Gators BBQ Team
Medium Amazin' Blue Spicewine - It's a Swamp Thing
Large BGE - Adopted
Medium BGE - Adopted
Weber 22 inch w/mods
Weber Genesis Silver C Gasser
Constant wood lurker