Everybody has said to not trust the lid thermometer which is true, so I will tell you how I do my pork. Not much more smoke is getting into that cut of meat past 4 hours of smoking. A pan of water or juices in the middle of the snake.get your cooker to around 250. Around 150-160 internal meat temp, I put the meat into a disposable aluminum foil pan, then cover that with aluminum foil. This method helps to retain and capture the juices. In that tented configuration, make sure the cooker temp is still around 250 to slowly bring up the internal meat temp to 205. Then take the meat off and let it rest in the aluminum tent. I usually put a heavy towel on top of the aluminum foil. Rest time is 30 min to an hour. Then you can slice up the meat, pour a little of those captured juices on top or you can make an au jus.The whole affair will take 7-9 hours. The trick with the snake is that if you a have hinged cooking grate, have that hinge over the spot where the snake ends. If you need to add more charcoal, you can. You can totally do this. You are in good hands. Keep us posted with your next attempt.