Original K0 "short neck" AT7B carburetor had three versions. The first change came at VIN #242074 in January 1971 and then changed again at VIN#270640 in May/June 1971. I believe the second change was the "tall neck". The tall neck required the taller slide, the shorter cap and the longer cable. I have only seen one of the late K0 carbs. As you can see in the photo, the neck of the K1 carb on the right is taller. The slide is taller and the cap is shorter compared to the K0 carb on the left. This is true for the 594A K1 4 speed and the 533A 3 speed carbs which were used through 1977.
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