Occasionally, you will find a John Deere 7000 planter with a serial number that doesn't fit the chart (e.g., 66,000 listed as both 1981 and 1982). This is due to "transition months."
This is the most common source of confusion. Unlike modern planters with a prominent VIN plate, the 7000 planter hides its serial number in one of two specific locations depending on the frame style. John Deere 7000 Planter Serial Number Year Of Manufacture