Farmall Cub

been running fine, but when I started it up today it idled funny and after a short time, smoke comes out of the dipstick and water comes out of the overflow. Engine sounds like it's in a real strain, but oil pressure is still good. Can't find any signs of water in the oil. Anyone have any ideas on where to start or what to check??

Possible head gasket.

Does sound like a head gasket...compression leaking into water system. I think there is a simple kit to detect these gasses in your coolant? I had a similar problem on my wife's Suburu. MUCH more expensive to repair than a Cub!