I got the details from another kit builder, including all the dimensions. I spoke to CC after sales about it to see if was a possible cause of my vibration, who initially where unaware of the enhancement. They later confirmed after checking with the factory the enhancement was for gearbox clearance and not prop working angle. Adding that spacer would be way cheaper fix for my car, so it would have been in CC's benefit to do so, but its not even being considered. At the moment is doesn't even have a part number (or one that has been published), so you can't even get it from CC parts, but when you can, I will be adding one to my car (at my cost).