126 Update:
Me and the Boys spent this evening tearing out the engine from the 126. I was leary of the narrow frame deal and the difficulties associated with it, but it was VERY straightforward and an easy job. One lesson learned was that when you are taking off the cast iron zig-zag grill, you might want to have a hand steadying it - else that heavy thing will tumble to the floor quickly, mashing whatever fingers and toes might be in the way...
Once we pulled the engine out of the tractor, we set it on a bench and pulled the oil pan. The pan was cast iron. My WF tractors have aluminum oil pans. Wonder when IH made this change...
When I pulled the oil pan, you could see the piston rod was broken in two places, at the top of the cylinder and at the rod bearing/crank. The crank looks very scored and has much aluminum build-up on it. I don't think I'll be dodging a bullet on this engine, I'm going to have to shell out some serious $$$'s or find a donor.
I was surprised the engine had balance gears. The service manual says only the 147 had balance gears - if I read it right.
Between the cast iron oil pan, balance gears and a black painted S/G, I'm wondering if this is the original engine or a replacement from another year make.
I'll try to post some pictures tomorrow of the debris.