K-Frame Question

I have a '67 Barracuda. It needs a new Idler arm and Pitman arm. I'm finding that the '67 is one year only. Does anybody know what make's it one year only is it the idler arm and center link or the K-frame? I could hardly believe Chrysler would have designed a K-frame 1 -yr only. Can anybody shed some light on this topic. Somebody has had to have delt with this already?????? Thanks.