Is this a '70 only item? I have never seen a blue early Z air cleaner. I noticed there is no "Winter-Summer" control on it, and no carb heater duct connection.

http://cgi.ebay.com/ebaymotors/Datsun-Z-240Z-Rare-Blue-SU-Carb-Air-Cleaner-Housing-OEM-_W0QQcmdZViewItemQQhashZitem5d2f1fbeb7QQitemZ400222568119QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Without getting into the reputation of that particular vendor, I can say that many of the replacement airboxes as sold by the Dealer parts departments were blue, not orange. I suspect that one is an example of a factory replacement.