Preheat a grill.
In a small bowl, mix brown sugar, garlic salt, mesquite spice, and the rub. Rub mixture on both sides of the pork chops. Place pork chops on grill and cook on both sides until pork reaches an internal temperature of 150 degrees F, about 5 minutes on each side (cooking time will vary based on the thickness of the chops). Remove from grill and let rest for 5 minutes before serving.