The C60 engine is an inline 4 cylinder engine. The cylinders are numbered from the radiator to the rear of the tractor in the following order: 1,2,3 & 4.I talked to a friend today that is in the local antique tractor club. From what I told him, if both 1 and 3 are next to each other, he thinks that the head gasket between the cylinders has opened up letting them cross over to each other?
In any event, It appears the next step is to remove the head.