Trim the fat from roast. For rub, in a small bowl combine salt, oregano, thyme, paprika, garlic powder, onion powder, white pepper, black pepper, and cayenne pepper. Sprinkle rub evenly over roast; rub in with your fingers.
For a charcoal grill, arrange hot coals around a drip pan. Test for medium-high heat above the pan. Place meat on grill rack over drip pan. Cover and grill for 1 to 1-1/4 hours or until medium-rare doneness (135 degree F). Add additional coals as necessary to maintain heat. (For a gas grill, preheat grill. Reduce heat to medium. Adjust for indirect cooking. Place meat on a rack in a roasting pan, place on grill rack, and grill as above.)
Transfer meat to a cutting board; tent meat with foil and let stand for 15 minutes before carving into 1/4- to 1/2-inch-thick slices. The meat's temperature after standing should be 145 degree F. Makes 9 or 10 servings.