What BD said. I went 9 hours at 275-300 for a 12lb brisket, and there was still 1 to 2 hours left in it. My snake wasn't that large either. I also by instinct and experience doing indirect on a kettle, rotated my exhaust during the cook to keep it opposite the fire.
Cooking a pork butt should be an easy task on a kettle with the snake method.
Modded Brinkmann Gourmet. Basic UDS. Rescued 22.5" OTS. SJS Mini-WSM. Stubbs. B&B Oak Lump.
Cannondale 2009 F8 (for burning off all the great BBQ)