340 K Member ??
Alrighty, my 70 340 Swinger with 4sp has both washer and sway bar.
My 72 Swinger 340 Special with auto has both washer and sway bar. The Kmembers on both are original to the cars. The 70 is disc brake and the 72 is 10 inch drums. The 70 has torque boxes on all 4 corners and so does the 72 hmmm, could it be something to do with torque boxes?