Soak wood chips in water 30 minutes; drain.
Combine pepper, garlic powder, salt, and mustard, and rub evenly over both sides of steaks. Place coated steaks in a large zip-top plastic bag; add Worcestershire sauce. Seal and shake to coat. Marinate in refrigerator 30 minutes.
Prepare grill for indirect grilling, heating one side to low and leaving one side with no heat. Maintain temperature at 200° to 225°.
Heat a large, heavy skillet over high heat. Remove steaks from bag, and discard marinade. Coat pan with cooking spray. Add steaks to pan; cook 1 1/2 minutes on each side or until browned. Remove from pan.
Place wood chips on hot coals. Place a disposable aluminum foil pan on unheated side of grill. Pour 2 cups water in pan. Coat the grill rack with cooking spray, and place on grill. Place steaks on grill rack over foil pan on unheated side. Close lid; cook 1 hour and 15 minutes or until a thermometer inserted into steak registers 145° (medium-rare) or until desired degree of doneness. Remove steaks from grill; cover and let stand 5 minutes. Cut steaks across grain into thin slices.