One of the quietest mufflers on a Kohler is the ones on a 210 John Deere Gt.
I had a 210 for about 10 years and it was as quiet of a kohler single you would want.
Also they were heavy/thick and long lasting. if You are going to modify one to fit, might look that way.
I guarantee you will not be not be disappointed with the quietness of it.
Some nice ones show up on ebay for less than you will pay for the one you linked. (used of course)
