Keith, last I knew, Kubota gasoline engines are basically the same heavy-duty block, etc as the diesels, but just setup for spark ignition and to run gasoline. My FIL had one in his shop (may still have it?) with thousands of hours on the clock and it purred like a kitten. IIRC, it was a liquid cooled inline 3, maybe a 2?
As said above, I'd avoid one because of the fuel consumption. Guaranteed you'll go through twice the gallons of fuel than a comparable diesel.