Whole chickens rarely go above six pounds. For a six-pound chicken, cook it on high 6 to 6 1/2 hours or low 7 1/2 to 8 hours. If you are referring to a baby turkey or whole turkey breast, the cook time for an 8 pounder in a crock pot would be 8 to 9 hours on low or 6 1/2 to 7 1/2 hours on high. When a thermometer reads 165 degrees F and the juices run clear, the chicken/turkey is done. Keep a close eye near the end of the cook time, because all crock pots cook at different temperatures and times.