Lynk’s Racing designed a cast head for the KTM 85 SX. The head is made out of much better material than other heads we have tested. In our testing, it runs 10 degrees cooler at the top of the head and it showed an increase in horsepower. We designed the head with plenty of material between the water jackets so you can design any bowl. Also, the water jackets are much bigger to increase the cooling capacity. We have seen many two-piece heads fail even when keeping the O-rings new.