About sand seal pulleys. Any pulley, including a steel pulley, that is cut for a seal may break from being reduced too small at the key area. I, personally, do not recommend cutting for a seal as only an off-road race vehicle that is submerged in mud or dirt may ever need such an item. After all, the pulley throws the dirt away from the center of the pulley and the crank case has a positive pressure in it to push the dirt away from the engine. The Type III has the return grooves almost outside the end of the case and could pull dust or dirt into the engine.
Furthermore, this is not an accepted method for fixing an oil leak. Only engines that have something else wrong will leak at the pulley. If you are committed to having a pulley seal we can cut our pulley, see LA PUL010. Full payment is required in advance