The obs trucks have a bracket that bolts to VC like in the pic, then a thin piece of metal with a tab that inserts in the bracket and goes over dipstick to hold it in place.
You could probably use a SD tube, but you would need the dipstick and tube because they are longer.
The pan nut is also clocked different on the OBS trucks too, but SD tube should be able to be tweaked enough to work.