hi sc
The cranks i've used are the 166 q factor, There's about 7mm clearance between the cranks and stays.
hope the photo's are what you need to see
thanks Madmick, that's exactly what I was after. Theoretically, a 156q crank could fit, but there'd be no frame flex room, and the drive side would probably be a bit tight with the chainstay protector.
I took a similar photo of my old ISIS Race face cranks on my carbon X and got similar clearance (could squeeze a 7mm thick pencil through on the non-drive side). This was surprising, given that my cranks are 161mm Q. Either I measured the Q-factor wrong or my cranks are thinner at the ends than those XX cranks (doesn't look it though). If you are interested, I'll be posting the photo on the "2010 Titus X Carbon - Would XT/XTR 2x10 work?" thread (I didn't want to clutter up your thread).
EDIT: comparing your photos with mine, maybe your cranks are a little further out - especially on the drive side. Either my cranks are offset slightly to the left, or my chainstay wrap is thicker than yours.
EDIT2: How did my post end up above your (earlier) post?