Preheat oven to 350 degrees. Place the pork, ham, cracker crumbs, eggs, milk, cayenne pepper, and onion in a large bowl and mix well. Shape into small balls, place on jelly roll pan, and bake for 30-35 minutes, turning once. Drain on paper towels and serve with sweet and sour sauce, or freeze and store in plastic zipper bags.
To serve, place frozen meatballs in large saucepan on stovetop. Add sweet and sour sauce and heat over low until completely thawed. Makes about 150 meatballs.
*May need up to 1/2 cup additional cracker crumbs if mixture is too moist