My single intake is about 3/4". The other two are one inch. If I open the second one, I run about 350-375, although the temp keeps creeping up. My exhaust is like a Weber lid. My other lid has a 2" pipe, which is over 2" ID. I had to add a 1/2" wide baffle in the stack to keep the temp down for smoking.
I'm very intelligent, but I mask it by doing stupid stuff.