2005 Mercury 50 59ci***Input Needed***

I have a 2005 Mercury 50 59ci. It is stock as of now. I was wondering what could be done to increase the horsepower out of the motor. Would like to get around 65 to 70 hp from the motor. I also would like to know if there is any other tiller handle options for the Mercury 50. I would like to have the gear shifter and tilt and trim controls in the handle.
Thanks

http://www.boatracingfacts.com/forum...-cu-In-Mercury

70 horsepower is easily attainable with some porting on the 59ci motor. Guys have adapted the new merc big tiller as well as the yamaha big tiller to these motors, both have the shifter and trim switch built in.