What dana67dart said. The engine mounts have to be changed for sure.
If you have a ‘67 steering set up you’ll have to change the idler arm. Other than that, you just have to keep whatever steering set up you have complete- so, pitman and idler and center link all have to be the same year range as each other, but don’t have to match the K.
The sway bar if you have one could take some work, if you’ve got the 67-72 factory LCA’s and stock sway bar tabs a ‘73+ sway bar won’t fit them. So you either need to use the sway bar mounting tab locatio from the 73+ LCA’s (add the mounts) or use a ‘67-72 sway bar, which will mean mounting it the same way as on thr 67-72 cars. So, adding provisions to the later K for the earlier bar.