Ported heads result in better flow of your air fuel mixture which then results in more horse power.It's a rather small increase for a lot of work and money unless your a serious racer I wouldn't bother. Cams open and close your intake and exhaust vavles, if you open your valves more you get more air fuel in and that gives you more bang in the cyclinder, more horsepower. A lot more economical, you get more bang for your buck.