dyno charts mean nothing all a dyno is this its gives you a base line so you can tell how much hp you gained by adding a new part and you have to test the same day so many factors like temp humidty change the numbers also some dynos will give you higher numbers then others some will give you alot lower numbers there just never acurate
i duno what kinda porting you have but 60 hp for a ported bike isn't all that bad dyno could have been a little low that day depends on what style porting you whent with and who ported it