Joe,
Reviewing several of the IPL's (thank you again Mark) It seems like the crank and con rod are the same, while the piston and cylinders are different.
That leads me to believe that the p/c's are interchangeable and the bore diameter is the factor responsible for the power and cc increase.
I'm sure that Mark will be able to refute or confirm this when he shows up.
Mike
That's what I was thinkin. Maybe it is a 2.3?