I just remove the water pan entirely to get high temps in the WSM. That gives plenty of clearance between the coals and the top grate. The fat drips into the coals just like a UDS and gives a different flavor to the smoke.
I cooked the Big Chop, ala Cooper's Old Time in Llano, Texas, this way a few weeks ago at 400 degrees and had no trouble maintaing the high temperature, although it was for a much shorter time than you will need for brisket or butts.
I would figure on having to add more lit coals at least once.
Jim - Another transplanted Texan
Former KCBS CBJ
Large and Medium Big Green Eggs , Black 18.5" WSM, Blue Weber Performer - Stainless, Green Weber OTG Kettle , Brinkmann SnP Pro, and a Stainless UDS. One retired Portable Kitchen grill.
Red Thermapen, Maverick ET-732, EdgePro Apex Sharpener.
Avatar is the original 1951 Weber Kettle
Last edited by HeSmellsLikeSmoke; 05-22-2009 at 11:07 AM..