At 350oF, you should roast a whole (thawed)chicken for 20 minutes per pound, plus 15 more minutes. If stuffed, cook the chicken for an additional 15 minutes.So for a 4.5 lb stuffed chicken, you should cook it for 2 hours.ou cook a whole chicken in an oven at 350 degrees. It is  recommended that for each pound you cook twenty minutes. Therefore  a 4.8 pound chicken would cook for almost an h … our and a half.