The longer cam bolts were an improvement, but not a fix-all. The older cam columns could crack with either length bolt, but this was a problem usually identified with the turbo fins. If your bolts are not staying in position, you can fix this by removing them, cleaning the cavity, and dropping a little Marine epoxy in the cavity, then reinstalling the bolts. Be sure to not use too much epoxy or you can glue your cams in place. Also, make sure you have the correct cam height set before the epoxy sets. Since the epoxy serves more as a space filler than a heavy duty bond, you will still be able to remove the cam bolts later if necessary. Still, it will be strong enough to stabilize the bolts.
You can also reinforce the cam columns. With a little search, you will find plenty of advise there. This should compensate for the shorter bolts by stiffening the columns.
Congratulations on your Outback!
