3320/40 from serial number 8351
4320/40 from serial number 5501
6320/40 from serial number 10201
7320/40 from serial number 4501
Application: Refer to parts book, 3320, 3321, 3340, 3341, 4320, 4321, 4340, 4341, 6320, 6321, 6340, 6341, 7320, 7321, 7340, 7341