Apologies for not posting here earlier; I just found it.
I have a 2165 tractor, with the 48", model 301 deep deck, that I purchased new in '98. I've always regretted not spending the extra ~$250 to get the 18hp 2185 with the Kohler engine; 16hp is not enough to power the 48" deck. Since the first year of operation, it has had an oil-consumption problem, which was greatly exacerbated by a mouse-nest around one of the heads. At the end of last year, it was using nearly a quart of oil per mowing, and mandatory spark-plug replacement after about 3-mowings. Over this past winter, I decided to repower it with a 22hp Predator engine, and after 8 months of on-and-off work, I finally got to mow with it the other day, and I am quite pleased with the results with my Frankenmower. I still need to build a new exhaust so I can use the hood.