OK - I came home today and took off my two risers. Put the ball valves on the pipe nipples on the bottom of the drum ( 3 of 'em) and lit it up. I've not been able to get past 210, but right now, with only about 1/3 of a basket of old lump, my drum is humming along at 260. My exhaust holes are equally spaced around the outside of the lid (5 - 3/4" holes), and the outside thermometer is reading 260 and the inside one, in the middle of the grate is reading 270. I'll cook on it this weekend (new WSM won't be here yet) on see how the temps do then. For now, lower is better!