this is the 3rd xr250 i've built and the one iv'e got in the garage stripped down is now calling me, had the frame shot blast ready for coating, pulled the engine apart ready to put a nice 277 in there and the bloody head is cracked, does any one have a spare engine knocking about at the back of their garden shed? or can anyone point me in the right direction for a cylinder head. it's the oil in the engin model xr - rvfc engine 2inlet and 2outlet valves.