It's my understanding that the 212cc Ghost engines were created for the Kart racing world to try to create a new mild performance / 'stock' engine class... (something fun & 'stock' that everyone would agree to use to keep racing costs down).
From what I remember, the Ghost engine comes with a stronger cast aluminum connecting rod, flat top piston, mild cam, stronger cast flywheel, & a small Mikuni style carb.... (it's nothing hard core).
Given a choice, the next small block that I build would start with a 224cc Predator because it comes from the factory with a stroker crank & a Tillotson style block.... then, for a just little more money in parts, you can build a much better engine than the Ghost!
As far as the 212 Predator, the 224 or the Tillotson... the governors are all very easy to remove... but you'll still have to beef up all the internal parts because they aren't designed to take the high revs... (the Ghost can).