Original head removed from a 1HP Rock island built engine, I believe it’s the same head he 1 1/2HP models used as well but please measure your engine before purchasing!!! Valves move freely and look very usable! Definitely need lapped/seated in before installing! Center to center head mounting bolt hole spacing is 3 1/8. Will need new exhaust and intake springs. Please keep in mind this part is over 100 years old and is not new condition! See pictures for the absolute best description. Rock Island Alamo Empire.