I am trying to find this small filter either through Summit or Amazon. I have searched all the threads back to 2004 and cannot find a part #. Datsun Parts is smart and have placed their sticker over the part number. I know they have to make a profit and all but its a $20 filter max, not $33 + $10 S&H. Its definitely not a 5" breather as the packaging shows, more like 1.5" I would guess. I know many members have these on their Z's and want to do the same on mine so I can ditch the over sized breather on it that looks to be more at home a BBC dragster. Any direction on which one it is will be greatly appreciated.

http://www.ebay.com/itm/Datsun-Nissan-510-620-240Z-K-N-New-Valve-Cover-Filter-/400307200264?pt=Motors_Car_Truck_Parts_Accessories&hash=item5d342b2108&vxp=mtr

If you are referring to those small cone-like filters, make sure you get one that will ft a 5/8 inch tube. the ones you see in the auto parts stores only go up to 1/2 inch, and you can't force it on without bending it up. I even tried to order the one I needed, and no auto parts store I tried (Autozone, O'reilly, NAPA) didn't even have it in the catalogs. So it looks like you need to get those through eBay (China.)

Thanks for the heads up TomoHawk. Looks like I found what I need. Shows to have a 5/8 inner diameter flange. I will probably pull the trigger on it tomorrow.

http://www.ebay.com/itm/K-N-62-1340-OD-2-in-Oil-Breather-Caps-/140787111780?pt=Motors_Car_Truck_Parts_Accessories&hash=item20c790d764&vxp=mtr

If you go to the K&N website, you can find exactly what you're needing.

http://www.thezstore.com/page/TZS/PROD/CP/10-2092

There you man enjoy

That item in #5 is "for off road use only." I don't know of many Z cars that are use for field-bombing...

In any case, I like the tapered style filter, for hood clearance purposes. Unfortunately, none of the U.S. manufacturers have the ones we need for the cam box vents.