It was interesting that in the novelization of Star Trek The Motion Picture (which Gene Roddenberry wrote), he said that Admiral Kirk (who was receiving telemetry of the Klingon attack via an implant in his brain) noted that the K't'inga class battlecruiser had larger photon torpedo tubes than the old D7 class.
I would also think that a K't'inga probably carries more torpedoes than a Constitution class starship, since K't'ingas are warships, and Connies are supposedly not.
(It was also interesting to note in that same novel...again, keep in mind the novel was written by Roddenberry...Kirk mused that the Enterprise's designation as a "heavy cruiser" seemed improper. Kirk felt Enterprise should've been designated a "battleship".)
If I remember correctly, the Vor'Cha is supposed to be roughly about the size of an Ambassador class starship (Enterprise C).