340 K frame with swaybar cutouts

Hi Everyone

I am restoring a '71 340 Demon. Has anyone ever seen a k frame in an A body with the sway bar cutouts as seen on an E body? The car has the A body sway bar mounted in the usual position, with the tabs on the lower control arms etc. Just wondering if this could have been swapped out sometime during the last 45 years, or was mother Mopar known to sneak a few of these in during production if/when parts ran scarce?

Thanks