Having no experience with these modified VW engines myself I cannot defend their claims, nor can I deny them. Just thought I'd show what they have on their web site.

BTW: That 120 HP isn't sustained full power, just for takeoff.

IMO I wouldn't call it a VW engine anymore, not with all of the modifications they have done to it. The size of the jugs and all of the changes to the original engine (including vastly increased cooling) determines the power rating of the engine, not the crank shaft. That is, assuming both it and the other original components, what ever is left of them, can take the increased stresses.