if you run it upside down it will contact the parallelogram.
You need a 165mm small air shock - old float ideally, narrow bit to the bottom with n adaptor on the top.
Right fiddly bastard of a job!
hmmm... there isn't much room for manouvre around the top mounting bolt for the shock on the Crosslinks, around the lower mount there is plenty of space though. The linkage hitting the shock body is my main concern, hence I've ruled out coil/air shocks as there's not enough room from what I can see. But the linkages and shock should all move in unison, so if the shock fits happily when the bike is stationary then it should be fine when compressed by a bump, no?
I measured the eye-to-eye length of my Noleen NR2 on the Crosslinks at approx 205mm. When you say you need an adapter making up, and to use a 165mm shock, what do you mean? any pics of one fitted?