It sounds as though your carburettors have been replaced with sidedraft carburettors (maybe Solex PPH, Weber DCOE, Dellorto DHLA...?). This would be considered an upgrade.
While the build data plate in the car may specify 2T-B motor, if sidedraft carburettors are fitted the motor may in fact be 2T-G, which installs in the same mounts and transmission as 2T-B. Is the motor head cover domed over or more square?
In Australia parts are no longer available for this car through Toyota.