All right, just to update this thread again. I installed the K&N intake on Friday...
I used part number #08698 to attach to the throttle body as the engineer at K&N insisted. Here's my feedback....yes the hose is a little too large in diameter but when I tightened it down with the hose clamp it was just fine. It is not going anywhere.....I tried to pull it off and there is no way it is going to come off with a clamp on it, there were also no air leaks after my complete install at this point.
So in my opinion 08698 works fine.....with a hose clamp tightened on it. As Deaner and etom pointed out 08690 is a little tighter fit and I am sure will work out just as well. But I guess I will go with what the engineer at K&N says, so if it fails at this point for some reason I can take this up with them. Just make sure you have enough part numbers in your kit before you start install.
Install note: There is another mistake in the directions as well.. Just and FYI for anyone else installing this....
http://www.kandn.com/instructions/63-9029.pdf
Step 8 says to install bracket (070632)....But what do you know this is not the bracket in the kit. The bracket they ship and refer to in the parts list is Part W (07158) This bracket works just fine, just not labeled right in the instructions. Hopefully this keeps you from searching for a lost part like I did...
Install took about an hour - hour and half with the help of a friend. Took a while of looking at photos in directions, as they are photos for an '05 and i have an '06 and there are slight differences in hole location/tube locations, but everything fit great.
Bottom Line: Deaner and etom are right, the sound this has is pretty dang cool....As Deaner said the sound alone is probably worth it. I have notice a little more pep with the added HP. As far as gas mileage I am sure I will be a little low this tank, because I have been gunning it to listen to it, hard not to do!! It sounds mean off the line.
Thanks all for you info on this thread.....
Now onto that dang harmonic droning noise that occurs between 70-75mph, that has been discussed on other threads. And I have this occuring on my '06 (yes this was there before K&N install)