Brinkman offset horizontal. I've started modifying accordeing to what I'm reading here, but still not having much luck. I just smoked to 12# turkeys yesterday (early thanksgiving). They came out pretty good, but I'm not happy with temps in the smoke chamber. I installed dial thermometers in each end of the smoke chamber lid, just above grate level, made a lid seal out of hi temp silicone, added a diverter from just above the firebox inlet angled down under the meat grate. Following the advice on the minion method from a link I found here, I cut a piece of expanded metal that lays at an angle in the firebox from grate level to above the damper in the end door to keep the lump from spilling out the damper opening. I filled the firebox up with lump to the bottom of the smoke box inlet, formed a dish in the center and added a chimney of hot coals to the center. My chimney is home made, and about half as tall as the store bought, so I added a second chimney of coals as soon as they were ready. Heres the problem - when I get the far end of the smoke chamber up to 250, the firebox end thermo indicaes 425. Th brinkman has two meat grates, and my diverter runs from the firebox to just short of the second grate, so just about half way. The left end of the first meat grate actually rests on the diverter. I'm thinking the diverter is acting like a flat top grill, and getting so hot that it is a stove in its own right. I tried drilling a bunch of 1 1/4 holes in the far end of the diverter - that didn't help. I'm going to try bending the diverter to make it "dive" down sooner and see if that helps. Any more ideas? The minion method of placing the charcoal and adjusting the damper seemed to work pretty well, but I just can't get that left end temp down.