Its an older Kohler 42'' 15.5hp, not sure on model number off the top of my head.
Umm it does have a pulley right on the top of the rear end but when i got the mower the guy said there should be 2 levers or something i adjust the pressure points and thats all there is to, to make it go faster. But i do have 1 pully on top its about 5'' wide.