Many folks advise that the timing belt be changed after 50,000 miles. If it does break your engine will self destruct. In changing the belt there is a proceedure for checking the timing and you can set the pump timing for optimum performance (power, mileage or whatever).
Don't exceed 3500 RPM!
These engine are BSH tough and will last a long time. I have 220,000 on mine now.
Regards!
Eric