This is my first cook with my BPS Drum Smoker. I am doing 2 whole chickens. The thermometer seems to be about 10-15 degrees lower than the grate where the food is. Also, is it normal that the temp falls once you pit the meat in it? I was assuming it was because there was more in the smoker to absorb some of the heat. Finally, what and where can you place a drip pan?