Wow thats great!! I believe the bore and stroke is still stock or perhaps just slightly increased. Cause the engine does not allow much increase in bore.
However, for 170HP on wheels it will be around 190-200HP on the crank. Thats very impressive.
For it to be still NA, its quite a feat. Downside is that definitely need to rev till very high RPM to achieve that power and low end will most likely suffer.