| Have to say I agree with Beancounter. It seems an awful lot of trouble to go to for an extra 30 cc. And you have to mess around to sort out the piston travel to make sure that the extra 2 mm stroke (1mm each at TDC and BDC) won't result in any piston to head contact either by fitting thicker base gaskets or using different pistons.
If I had the dosh to do this I think I would spend it on tuning the standard motor - maybe some gas flowed heads and getting the cams dialled, that sort of thing. I would look to build a sweet running reliable motor that's maybe got a few mods, been built carefully and with all it's tolerances spot on than build something like a grenade with the pin half way out | 
Jools
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