its roughly the same size engine ( actually smaller in capacity 15hp compared to original intek 16.5) but it is wider across the front due to the large muffler and air cleaner box - had to cut a bit out of the bonnet to fit over the air cleaner.
I agree its not a fault with kohler, more of penny-pinching not to thread the holes themselves, the real fault lies with me for not discovering the blind-hole mounts before buying it...live and learn

this shows the other side and big muffler
[Linked Image from i1118.photobucket.com]