I have a setup for the 250 that should make it really run. The Bigbore is done and in Gilles bike, his is a 285 and can go to a 301.
I am working on a stroked big bore that should make for a more mild power curve. Its in the final stage of R&D.  Stroking a 250 creates some issues that need to be adressed I have been working on this when I get time for over a year to get it rite.  When I get it all done It will start as a 293 or 301.