PM Terrence, handicapped racer, he knows more about these things than most have forgot.
The 04/05 600 and the 750 are the same essentially except the engine. The 750 engine will bolt into the 600 frame and make an awesome cheater bike for the 600 class. Many people have done this and a few have been caught.
They are rock solid race bikes. Parts are plentiful and inexpensive, I like to think of them as the Chevy small block of motorcycle racing.