Lilandra, welcome!
I'm not sure about this, but I think the Torso is in the cellar of the house in the Bridge district, somewhere at the bottom of the district map. I might be mistaking it with the Arms&Legs, if so: the other location for Kangaxx's bodyparts is in the Temple District Sewers. (You need the Unseeing Eye quest to get there). Good luck!
------------------
Melusine, Archbabe of the OHF and the LH
Your voice is ambrosia