i found this on ebay
http://cgi.ebay.com/ebaymotors/ws/eB...2855183&rd=1,1

33k miles and 6180 hours somthing doesn't seem right here..

i'm not sure what avrage MPH is. but i do know guys usually replace these engine in boats around 10,000 hours. granted a boat has a reverse gear and not a transmission so the engine works harder.

 

That was used as an airplane tug...probably has 6.17 gears or so in the rear. Don't go to awful fast...just pulling flyboys.