There are no cons. This spark plug, according to my 1960 Champion spark plug chart, was for certain Ford product trucks and buses manufactured during the 1956 and 1957 model years. I bought this spark plug for a collection I have started of Champion spark plugs, of which there have been many, many types, the costliest of which are for aircraft applications. Right now I am restricting my collection to the 18mm tapered set types.