Pitman Arm Compatibility
Here's what this all boils down to. From 67 and later, the 67 unmodified K frame is unique and takes a "one year" IDLER arm. This means if you do not modify the 67 K to take a later idler arm, you must use the 67--72 steering linkage
If you have ANY K member from 68 later, OR have modded your 67 K to take the later idler, NOW you have the following situation
The PITMAN arm, the IDLER arm and the CENTER LINK are going to depend on whether you have / can get an early or late that is small or large spline steering box.
In other words THOSE FOUR PARTS must all go together. They are split between 72 and earlier and 73 and later
Here's some info:
http://www.bigblockdart.com/techpages/techindex.shtml
http://www.forabodiesonly.com/mopar/showthread.php?t=236925
In other words whatever steering box you use you MUST have a pitman to fit, and that is determined by the spline size. The other two pieces, the idler and center link MUST then match the early or late pitman, whatever you end up with. Other than 67, the year of the K member DOES NOT MATTER.