[Yosemite Sam]

I personally have never seen it written anyplace where an original ever came with anything other than a 7 hp engine. The 8 hp engines were used as replacement engines when the 7 hp engines were no longer available.

My parts book states that "Complete replacement engine will be Kohler K-181" it goes on to list two different spec numbers along with two different part numbers.

I would bet that the original carburetor/air cleaner were replaced sometime and no one remembers.