Hello McDonald and Chief,
I have hopefully some info that might be able to help. I also am attempting to replace the stock air filter element on my 07 Ultra. The K&N stock replacement is a HD 1499 HOWEVER you need to wait for the corrected version with properly spaced breather holes per HD OEM specifications to be produced in about two weeks.
The HD 1499 has breather holes at about 4 11/16 " center to center instead of the approx 5 " required by HD OEM specs and to be able to mount the element without compressing the two rubber breather hoses. I have been battling K&N for 2 + years on this and finally two weeks ago received an email from their R&D boss acknowledging that I had been correct. They are in the process of changing the production mold and will test it at their end and then forward to me to test. FINALLY !!!.
The stock HD OEM 2008 air cleaner element is different from 07 and earlier due to a larger throttle body. Would like to have that throttle body on mine!
Not sure that K&N has the stock replacement for the 2008 as yet.
I have been using the SE 29509-06 air cleaner element as it is from the 05 SE 103 air box. Not sure if it makes alot of difference but the element composition is alittle more Hi Flow looking. Problem that developed last week with it when I checked it was that the filter material was actually gone from the bottom center pleats and the outer two corners heavily stained due to the famous oil misting that can occur. The dealer informed me that there were shipments from HD suppliers to dealers throughout the US of defective air cleaner elements for many part #'s with the same kind of material failure due to exposure to fuel and oil. They are replacing it for me but it will only be an interim until I finally get the virtually indestructible K&N HD 1499 (NEW VERSION).
It's been a frustrating experience for the last 2 + years but the end is near. Then of course the 08 is different but hopefully they correctly spaced the two breather holes.
Hope this helps both of you.