In a large pot, add the beans, salt pork and onions
and stir together. Cover the beans with cold water by 1 inch. Bring the beans to a boil, then reduce the heat to a simmer and cook for 1 hour. Add the vinegar, seasoned salt, salt and pepper. Continue to simmer
the beans, stirring occasionally, until tender, about 1 1/2 hours. Season to taste and serve hot.