A body K member

Just buy the swap mounts for your '72 K. If you must buy a K, then '73-76 is the way to go as already mentioned. The '73-'76 K has the better spool mounts for the engine, and the sway bar runs through the K frame which improves ground clearance.

But yeah, also no issue with just running /6 to V8 conversion mounts for your current K frame. The '67 is the worst choice of all your options.