Combine all seasonings in a small bowl and rub evenly over roast.
Prepare a medium fire, banked, in covered grill. Position pork over a drip pan, add about 1/2 inch water or apple juice to drip pan. Grill over indirect heat for 3 1/2 to 4 hours, until pork is very tender. Add more coals as needed to maintain a grill temperature of about 300 degrees, but avoid opening grill often.
Remove pork to large cutting board or platter and let rest for 10 to 15 minutes. Slice or chop to serve.