I bought this 96 ls about one year ago. It now has 59K miles on it. I heard the timing belt needs to be changed at 60k. Will it last to 80 or 90k? I had a Ford escort with over 135k on the original timing belt before I sold it. That car was only three years old, all highway mileage. This car is over 7 years old with more city mileage. Would that make a difference in making my decision on when to have the belt changed?