The bolt pattern on the base of the RS cylinder is the same as the NSR, so in that respect, any machining of the cases could be argued that it was entirely for performance purposes, not for fitting of the RS cylinder... er, technically!

If I remember correctly, the base of the cylinder needs to be cut to clear part of the casing, but I will make some enquiries to find out for sure.

Watch this space!

Andy.
NSR-WORLD.COM