none of the above. Possibly a Dana 91 or 90 (Chrysler Marine) however defiantly a Dana may also be badged as Chrysler 300
Still RUN
OMC drives wouldnt handle the torque of a Cummins 6BT and could never be paired with it and live. not sure the Dana could handle it either as the largest motor the Dana was ever paired with was a 440
remember, there are other drive manufacturers
Out of Business:
OMC, Dana,
Still in business:
Stern drive manufactuers - Mercruiser, Volvo, Yanmar, Yamaha (just not in North America)
Sail boat stern drive manufacturer - Sonic, Volvo
Inboard Trans - Borg-Warner, Twin Disc, ZF, Volvo, Hurth, PCM, Velvet Drive
Racing Stern drive manufactuers - Mercrury racing, Imco, Ilmor (Indy), Konrad, Teague, Max Machine works
Surface Drive manufacturers - Twin Disc (arneson), Weismann, Levi, Power Vent, Pulse Drive, Q-SPD
Here is an old link to drive manufacturers -
http://www.rbbi.com/links/drives/sterndrive.htm,
http://www.boatdesign.net/Directory/Propulsion/Drives/