I know this is an old thread, but I still wanted to put in a couple of comments about a receint experience that I had smoking sirloin tip. A grocery store near me was running a sale on sirloin tip, so I thought, "what the heck, I'll give it a try." I wanted to pull it, but still retain moisture. After reading various forum entries about smoking sirloin tip, I came to the conclusion that that really wasn't possible using traditional methods, so I decided to go a somewhat non-traditional route and it turned out excellent. Here is what I did:
Using a 4 lb piece of sirloin tip, the night before, I put a dry rub on the meat and placed it in the refrigerator, uncovered, over night. The next morning, I fired up the propane smoker to a temperature between 200°-220°. Once the temperature was steady, I put the sirloin tip in the smoker and smoked it for about 4 1/2 hours using apple wood chips. I then removed the meat from the smoker and believe me, it was tough. Now here comes the unconventional part. Once out of the smoker, I coated the top of the meat with about 1/8 cup of bacon grease and placed it in a slow cooker. I didn't add any extra liquid. The smoked sirloin tip stayed in the slow cooker on high for 3-4 hours. Upon completion, I shredded the meat along with the few juices collected in the bottom of the slow cooker. The result was some of the best BBQ beef that I have ever had. It was juicy, moist and flavorful. I will definitely be using this method again.