Oliver mounted plows with start number 3. Two examples would be a 3241 which was a popular 3 bottom and the 360 series which were introduced in the fall of 1962. Plows starting with the number 4 are pull type plows such as the 4340 which was also popular at that time. The 4440 is a pull type plow with a pipe back bone. Later it was also made as a 4441 which could also have an on land hitch. Plows starting with the number 5 are semi-mounted plows. Plows starting with the number 6 are roll over plows.