this post says its a standard bottom end, pistons in the previous pictures of the bottom end look fairly standard and arent dome tops as i would expect in a high comp bottom end build.
no signs of a VCT mod that i can see (your "b-cam" was discussed before)
pictures of the head look to me like it has had a reasonable whack of meat taken off the bottom of it. if the car is running corn juice or race fuel only im thinking even higher than 10:1 11-12?
if thats not it at the moment im not sure what else it could be to give that big of a change