that part number appears to be for a strut for a 300gt. it doesnt look like its threaded or an insert
http://www.bilsteinus.com/cart/index.php?main_page=product_info&products_id=2745&zenid=
they do however carry inserts for other cars like vw gold, camry, etc. not sure on how the measurements compare to the b13/b14 struts though
http://www.bilsteinus.com/cart/ymm.php?zenid=&keyword=insert
Edit: ok, well im an idiot, forgot the this picture may not be actual product caption. ill do some more research
http://www.bilsteinus.com/cart/index.php?main_page=product_info&products_id=2745&zenid=
they do however carry inserts for other cars like vw gold, camry, etc. not sure on how the measurements compare to the b13/b14 struts though
http://www.bilsteinus.com/cart/ymm.php?zenid=&keyword=insert
Edit: ok, well im an idiot, forgot the this picture may not be actual product caption. ill do some more research