Ski Doo 800ho billet head with interchangeable dome inserts. This head adds 10hp in the mid range and 6hp at peak rpm over stock with 13.5:1 domes.(5000-8000′) Other available domes: 12:1(low elevation) 12:1(turbo) 14:1 (high elevation 8000’+) 15:1 (race) This billet head will give you improved cooling capacity and better throttle response. Available in black, blue, or orange anodizing. Also available dome inserts for 830 and 860 bb motors.