CC,
Dyno readings may rise and fall, todays reading is no guarantee of horse power in the future.
Two dynos, same bike, different results, it happens all the time. There are a 1,000,001 reasons for this. On the other hand you might get the same reading.
The only way to know where you are at for sure is to have two bikes on the same dyno on the same day. Even then there are some variables run to run.
Ignoring the "dyno factors" HP at the wheel is not solely related to the sum metal parts of the engine.
Ray.