There are 3 different types of driveshafts for these. Make sure this is the one you need
John Deere 300 312 314 316K - driveshaft assembly..complete
John Deere 300 312 314 317 - H2 control valve
John Deere 300 312 314 317 - H2 Hydraulic control valve
John Deere 300 312 314 - pair of throttle/choke cables
John Deere 300 312 314 317 - gas tank cap/gauge