What is the problem? Is the angle too narrow (steep)? If so, a different gullet will help. If the angle matches, then a too wide shoulder would force the front end up noticeably, wouldn't it? If the problem is that it is too snug past where the tree ends, then wouldn't it loosen up with time? Do you have any pictures?
CAIR packets aren't very large, and can be removed and stuffing added.
Also, the folks who make it say "The CAIR Panel System requires that the rider be seated in the saddle to check even bearing. It is only when the rider's weight bears down that the air will fluidly move to hug the horse's back and distribute the rider’s weight evenly. An optimally fitting saddle will hug your horse's back, providing a close fit." http://www.cairpanelsystem.com.au/Fi...ttingSteps.htm
It is also possible to alter the fit of a CAIR saddle: http://www.cairpanelsystem.com.au/Fi...TheBalance.htm