mega parts list their repro hemi K frame as 71-72 B body and 70-74 E body.
I would think the upper K frame portion of the mounts would be basically the same as the 66-69 B body hemi K frame. As you mention they have different skid plates and different sway bar mounts.
I think the metal engine mounts vary between year and body but the rubber isolators are about the same.
Matt