I'm being told by this guy that the SC300 timiing belt is changed at 60k miles and the SC400 is changed at 90k miles... is this true? Tried search, didn't find anything.

60,000 is correct and where in FL. do you live because I might be able to save you some money on the timing belt job if you local..Let me know..

Flypen- if you really want to save some money, search again. You'll notice many posts about timing belts lasting way beyond the recommended change interval. I'm not sure about your engine, but on the SC400, the belt is easily inspected by removing a few covers. I do know the SC300 belt, like the SC400, is huge and solid- there is minimal risk in extending the change interval.

Go to the Gates Belts page,

http://www.gates.com/brochure.cfm?br...ocation_id=540

Download the file "Timing Belt Replacement Guide" found near the bottom of the page. Some good information is to be found there.

My belt was changed for the first time at 130k. It didn't break, I just got bored one day and decided to have it changed. I went with a Goodyear Gatorback belt, pretty solid construction...