Cut tiny slits in roast. Combine garlic and next 5 ingredients; rub on all sides of meat.
Cover and chill 8 hours.
Grill in a WEBER Charcoal Kettle or Genesis Gas Barbecue, covered with grill lid, over medium heat (300° to 350°) 2 1/2 to 3 hours or until meat thermometer registers 170°. Serve roast with Tangy Barbecue Sauce.
* Substitute your favorite commercial barbecue sauce, if desired.