Blend together mayonnaise, sour cream, white pepper and salt. Combine snow peas, baby peas, water chestnuts, bacon and red onions with dressing until ingredients are well coated.
Refrigerate at least 24 hours before serving. Stir twice each day to redistribute dressing.
Note: Peas must be naturally thawed. Slow thawing under refrigeration is best. Room temperature is acceptable, but do not place in water. Place the thawed peas on paper-towel lined pans and let stand at room temperature for 30 minutes to purge the remaining excess moisture from the peas. If peas are not thoroughly thawed or have been thawed in water and not properly drained, they will dilute the dressing.