Has this just happened or is it a photo from some time ago as it looks to be an old specification engine. Looking at the photo, it appears that it doesn't have any cambelt case ventilation as the gasket is in place and no sign of spacers or vent holes. It has a pre-mod crankshaft gear and bolt, the type that makes an unplanned exit through the cover. There is a kit to update these, many were done FOC by dealers. Prior to the ventilation mods there were several cambelt failures but since then very few, if any. This was a common sight once but it all seems to be reliable now. It doesn't need a chain or gear conversion.