12a half bridge cost and components
 

I am building a sand rail and am going to use a 12a for the power. I want to use a half bridge and plan on doing all the work myself. Typically how much will it cost to build? Will I need carbon apex seals and hardened stationary gears? Any other special parts to handle the rpms and power? What kind of power can I expect with a good carb and tuning? How many rpms will I need to get all of the power out of the motor?

Sorry for all of the dumb questions. Im not too familar with the 12a and havent built a rotary myself. Any help would be appreciated. Thanks.