I smoked a 12 lb turkey on Thanksgiving and it came out ok but when the breasts hit 160 the thighs were also 160 so I had to keep cooking. So the breasts got a little over done. I iced down the breasts for 30 mins before cooking but it did not seem to help. I cooked indirect on grate at 325. What else can I do to have the whole turkey done at the same time?