Thitek's GIIIH "Bear" Cast Porters version gives your cylinder head porter the added material to design a port around your specific combination. Intake and exhaust ports are untouched, as are the combustion chambers. Allowing your heads to be customized specifically for your motor for maximum performance, without the restraints of the OEM cast heads.
NOTE: These are un-assembled, cylinder head castings. Springs, valves, or other accessories are available, but NOT included.