Yes, it's a Gen III based design... '08s are Gen IV.
That filter is the same I currently use on mine. I have used the AMSoil one and from my memory it was just about the same length. The Delco ones have become a tad bit shorter over the years, not sure why...
With the superior media in the M1/K&N/AMSoil filter you're already ahead of the game as compared to most filters.