MIX salad dressing, sour cream and salad dressing mix until well blended. Add spinach, water chestnuts and red pepper; mix well. Cover. Refrigerate several hours or until chilled.
CUT slice from top of bread loaf; remove center, leaving 1-inch-thick shell. Cut removed bread into bite-size pieces.
SPOON dip into bread loaf just before serving. Serve with bread pieces, NABISCO Crackers and/or assorted cut-up fresh vegetables.