You will find life less stressful and your self a better cook if you let the pit do it's thing at the temp it wants to run at.
BBQ RULES FOR SUCCESS
YOU CAN NOT COOK GREAT BBQ ON A CONSISTENT BASIS BY COOKING TO AN INTERNAL TEMPERATURE OR BY TIME ( XXX MIN PER LB) YOU MUST COOK BY FEEL! For Brisket it must pass the poke test(probe like soft butter) Ribs pass the Bend Test, Pork Butts when the bone wiggles loose. These are the only reliable methods to ensure that your cook will be a success. There is one exception to these rules and that is Poultry which must achieve and internal temp of 170 deg in the thickest part of the thigh and 160 in the breast.
I never met a Cow that I didn't like with a little Salt & Pepper! Certified PORK-A-HOLIC