I don"t understand where some people get the idea that JD made a 4320 with the powershift trans. The few that have shown up on the internet, have all had the build code of a 4020 along with the serial #"s. So clearly its the back half of a 4020. All 4320"s build code prefix was T613, so if there was a so called 4320 powershift, the beginning of the serial number would have to have the correct prefix. All of the ones that have been posted on the internet have the prefix of T213 which is a 4020, and they were 1970 model years. 4320 was made in 1971 & 1972. Serial #"s don"t lie, Am I missing something here?