In large, shallow nonaluminum baking dish or plastic bag, pour ½ cup Italian marinade blended with reserved orange juice over pork. Cover, or close bag, and marinate in refrigerator for 30 minutes.
Meanwhile, combine tomatoes, orange sections, onion, dressing, parsley or basil, and salt to taste; set aside.
Remove pork from marinade, discarding the leftover marinade. Grill or broil pork, turning once and brushing frequently with remaining ¼ cup Italian marinade, until pork reaches desired doneness. Serve pork with tomato salad.