if i polish the head and the carb that can give me more power

 

Huh? yea, porting and polishing the head can make more power. If you are talking about your mojave there are about a dozen other things I would do first though. Full exhaust, clamp on filter, jetting, cams, high compression piston, and a whole bunch of chassis work(shocks, axle, a-arms or wheel spacers, etc) before I bothered with any head work. Just my opinion.....

 

You want to leave the intake a little rough,it helps attomize the fuel better. It will help on the exhaust side though.