As Stan says size do make a difference. I have searched all over and threatened to beat my grocer severally about the head and shoulders looking for three pound and under frying chickens. Not the 4 and a half roasting hens the packers pass off as fryers.
Can't be found for love nor money unless you raise them yourself. A 2 1/2 pound spring fryer is goooooood easy to cook and tender. Don't have to scorch the outside to get the inside cooked or soak it in hot grease too long.