ASW variant developed in 1958, armed with four torpedoes or APR-1 "Condor" ASW missiles located in two large pods on each side of the fuselage. The first prototype was built in 1963. (See attachments)
Another Mi-6 of this standard was modified in 1965 with an experimental towed echo-ranging sonar system and mine-sweeping equipment for the "Barge Hauler" program.
Development of some of the required marine equipment on these versions was delayed, resulting in them not passing state acceptance trials. However, they would continue to serve as flying laboratories for testing different ASW equipment and armament.
Are you sure those pods contained the armament in your description? Why conceal them like this instead of normal outrigged pylon-mounted practice? I've always assumed the pods contained some kind of ASW detection equipment.
I used to think so too, but upon closer inspection of the photos it appears that the pods have some kind of door at the bottom that opens like a weapons bay.