Wash hands. Combine dressing, cilantro and chili powder in a resealable plastic bag; add steaks. Refrigerate 6 hours or as long as overnight.
Preheat grill to medium heat. Drain steaks, discarding marinade. Grill steaks, uncovered and turning occasionally, 14 to 17 minutes for medium rare to medium doneness (internal temp 150-160° F).
Serving Suggestion: Carve steak into thick slices; season with salt to taste. Serve in tortillas with desired toppings, for example, shredded lettuce, diced tomato, sour cream and guacamole. Refrigerate leftovers.
Tip: To broil, place steaks on rack in broiler pan so surface of beef is 2 to 3 inches from heat. Broil, turning once. 10 to 13 minutes for medium rare to medium doneness (internal temp 150-160° F).