The reason why i asked about the 258 , is this section in the Cik regulations, copy paste from Cik:
7.2.2 Motorbike Grand Prix engines
Motorbike Grand Prix engines may be approved under the following conditions
they must have been designed before 2001.
As the 258 clearly is a motorcycle grand prix engine designed before 2001 ,but i guess someone would have to do the paperwork for the engine to be entered into Cik events, but I don’t know if it would be worth the hassle.
We are still discussing the price but we are getting closer, I just don’t want to pay too much for an engine I can’t use.