yep, it's not the blackburn but they all attach the same way. Mine is a topeak and it has a rail for a trunk. The silver brackets do not go far enough unless I tilt the rack, then the trunk bumps into the seat. The shop usually has, but is out of right now, a bracket of some sorts, that fits on the seatpost, and you can attach your rack brakets to those.

I think my hose clamp/bolt idea might work. The expedition has the rack eyes way down. I saw another thread where someones shop had extra long brackets. I have some darn long brackets but they are not long enough for the rack to be level.