I would definitely use the later model K just for the fail safe motor supports. A good engine can rip the left biscuit mount apart.
The later sway bar is more common too.
I haven't read all of the posts in this thread but I suspect you have learned there is situation where the pitman arm needed was never produced. Some steering gears simply cannot be connected to some center links when mixed ( somebody tried on your car ).
You have to determine what steering gear you will use and find the center link for that application.
