I'd either look of a good engine and save yours for extra parts if needed,
or find a whole donor tractor as Farmall did.
If your engine put a "window" in the block, it also did other damage that would be cost prohibitive to repair, and many parts are NLA.
One can use a KT series II or magnum as a "Bolt in"
The Magnum would need a simple wiring modification to stop the engine.
Others have installed "updated" OHV. engines.
IIRR Small engine warehouse (SEW) made a kit to install a newer OHV engine in them.
Me, I'm old skool, I like the opposed twin, but that was not your question.
