<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Chad McGrath:
My friend is giving me an 8lb butt and 10lb ball tip roast this weekend. I want to slow-smoke them starting Friday night. How long should I plan on cooking at 225-250 degrees? I am assuming it is best to put the beef roast under the butt. Any advice would be much appreciated. </div></BLOCKQUOTE>
For the butt, definitely go with 250 temp, especially if that is lid temp. 225 will add a few extra hours.
I've started mine at 250, had the temps drift up to 265-270, and still have a 7.5lbs butt take 15 hrs.
Butts are very forgiving, and you can get away with running a little hotter without any sacrifice in quality.