I don't think there's a lot of info out there on the Jap home market models. Parts could very well differ. All the 650 BS34s I've ever seen have the fuel "T" between them, but there are BS34s used on other models that are set up like yours. Maybe your carbs were swapped or maybe it's one of those Jap home market differences. Do you have a gas tank with 2 petcocks? If so, maybe that's why the carbs are set up that way. When the BS34s came out in the U.S. (1980), the gas tank was also changed to a single petcock version. So, you had one petcock and one fuel line feeding one fuel inlet (the "T") for both carbs.