Last month I threw a small sirloin roast in with the shoulder just for the hell of it, and it did not turn out well. It wont pull regardless because if you smoke it long enough to get to the "pulling heat," you'll just have a big pork hockey puck because it's so lean.
Even if you bring it to 165 your pushing your luck, thats pretty warm for any lean meat. My advice is to make a small smoker packet for your grill, get it smoking and sear the roast, then drop the heat, move the roast to the top rack and let it smoke until it gets to 150 or 155.