Trim fat from steaks. Place steaks in a resealable plastic bag set in a shallow dish. For marinade, in a small bowl combine vinegar, oil, ground ancho pepper, garlic, brown sugar, oregano, coriander, 1/2 teaspoon salt, and allspice. Pour marinade over steaks. Seal bag; turn to coat steaks. Marinate in the refrigerator for 4 to 8 hours, turning bag occasionally.
Drain steaks, discarding marinade. Sprinkle steaks with additional salt.
For a charcoal or gas grill, place steaks on the rack of a covered grill directly over medium heat. Grill for 10 to 12 minutes for medium-rare (145 degrees F) or 12 to 15 minutes for medium (160 degrees F), turning once halfway through grilling. To serve, cut each steak in half.