1969 to 1974 use the same style tank. Some of the early 69 tankes are hand formed and have wrinkles in the tunnel, these are called wrinkle tanks and are very expensive because they are usually found on sandcast bikes. 77-78 K tanks are a different shape.
In 1975 the petcock location changed from the right side to the fled and from a flanged mount to a screw on spigot (like a garden hose). Otherwise the 75 and 76 K tanks are the same shape and dimensions as the earlier ones. If you are going to switch to a 75-76 tank you will need the matching petcock.
