Galion 503 grader, what kind of gas engine?

Help! Looking for someone who may be able to identify the IH gas engine in a grader.

I recently bought a Galion 503 grader with a 6 cylinder gas engine. Engine ran great until it broke a rod and busted the block behind the carburetor. I need to find out what the engine is before I start looking for parts or a replacement engine.

It's an L Head engine. There is an IH cast into the block, so that's a sure thing. The serial number on the grader is "503-HG-04063". There is another metal...

Galion 503 grader, what kind of gas engine?

Galion 503 grader, what kind of gas engine?