So did this tonight. A couple of challenges, one was the weather, it was in the triple digit neighborhood today, although dropped to mid 70s once the sun went down.
two I needed to use both racks in the WSM
I salted, put up the chimney, rubbed and put in. had one thermo on top rack and one in the meat on the bottom.
was able to keep temps between 215-250 for the most part. internals hit 168, and when I tested the top rack it was just about 160. left it like that for about half an hour, and then pan wrapped, two to a pan, one per rack. This time I put the probe in the top rack one, which is a thicker cut. will try to bring grill up to 300, and leave it there for a couple of hours, hopefully by the time i go to bed it'll be 205 and I'll stick it in a cooler till I wake up, and then pull.
pics so far attached.