Yes, you can. You need to edit two files: Main_ComponentConfigurationSlotsPlayer.txt and SpaceObjects_XFiles.txt.
For the first I
strongly suggest you get SJ's Slotmodder.
http://imagemodserver.mine.nu/starfury Then add the new slots you want to the hull you want them on.
Second, you go into the space objects file, find the hull you edited before, and change its hardpoints. These determine where a shot comes from and what angle it can shoot at- a slot's firing arc cannot exceed the arc allowed for its hardpoint.