Well your search will be never ending due to the fact that they did not make an XB9R in 1995. They started production in 2002 on the XB's. Is it possible you are looking for a 95 Thunderbolt engine?
yeah, its a thunderbolt. Its for my cousin in Greece, and he blew the engine. Sorry for the confusion, i don't know much about bikes. He told me '1995 XB9R.'
There are several Buell message boards some that have classifieds area. There is always engines that pop up. Some one with a little more tech knowledge might be able to help, but I believe that you are not limited to just that model, and that other model engines will also fit and hook right up. You could also send your blown engine out and have it bored out, and rebuilt. Nalins racing I heard does a fair amount of engine work for a reasonable price.