A few years ago someone put a 288 top end on a 372; I'd expect the basic process to be similar.
Case was opened up to accept the "spigot", transfers widened to the point that crankcase compression might have been compromised. Bolt holes in 288 jug enlarged to accomodate smaller spread and some fins cut back. I think they had to mess with coil mounting too as spacing was off.
AS I remember the performance gain wasn't enough to justify the amount of trouble. A fun project for the enthusiast with skills and access to the right tools, but probably not a valuable product for the saw mod shop to sell.