According to some reading and using this utility using 40cc as the "Head Chamber Volume" and FLAT piston:

http://home.quixnet.net/~cosmic/EngineCalc.htm

I came to the following conclusions:

OEM
95mm bore x 61mm stroke = 432cc @ 11.8 compression ratio

450 Kit - "so called"
96mm bore x 61mm stroke = 442cc @ 12.05 compression ratio

450 kit, not legal
97mm bore x 61mm stroke = 451cc @ 12.28 compression ratio

460 kit monster
98mm bore x 61mm stroke = 460cc @ true 12.5 compression ratio

This makes sense to you guys? http://home.quixnet.net/~cosmic/EngineCalc.htm