I called Wossner today to discuss availability of their Pistons for CRF230s. They manufacture the Pistons in Germany and usually have the 67mm over bore on the shelf. This piston comes as a kit with the rings and pin, although the website doesn't specify. Their price was $150 for the kit which is actually very good. They also have the gasket kits with matching head gaskets. They ship a lot of these to Brazil and this size is very popular. It's also the same size as the BBR kit which is currently not available and the Wossner looks to be higher quality and lighter. They list a range from stock 65.5mm to 2mm overbore in .5mm increments. It's nice to know there are options out there for our bikes.