Once you cut into a piece of meat it is contamintated internally. Stuffing presents another place for bacteria to grow. To effectively kill off the potential growth of bacteria, your internal temp should be 160 degrees... reaching 140 in less than 4 hours from internal 40 degrees. There are basically two rules.. intact muscle rule and compromised muscle. If it's probed from the beginning, it is compromised. If it is brined or injected or stuffed, it's compromised. Intact muscle doesn't have to be taken to 160 because nothing has been introduced to the inside. There is a lot of great info on this in the safety section. It's not so much stuffed or unstuffed, more like compromised and intact muscle regardless of the method.