you could use those hubs and tap them to use the tread, but is there any reason you for 3 3/8 wheels, as you can get the 2-7/8 wheels in the t40 format which you can use with standard 3/8 unf JOINER nut, also you can get them in the uk http://www.robotshop.com/uk/rb-ban-94-orange-wheel.html.