I have a 2003 Subaru Forester 2.5 XS AT with about 68,000 miles. Our dealer is saying our left head gasket is leaking and should be replaced. We confirmed that with another independent shop. The dealer also suggested, as long as they`re "in there", they should replace the water pump, timing belt, and timing belt tensioners. Now I`ve heard that leaking head gaskets can be a problem on these vehicles, and that the timing belt should be replaced at 105,000 miles. My quetions are 1) should we replace BOTH head gaskets because of the tendency for them to leak; 2) should we replace the timing belt even though we`re 30,000 miles away from the recommended change-out time; and 3) are the timing belt tensioners routinely replaced along with the timing belt? A couple of othe mechanics we talked to said they could recollect changing tensioners only once in their careers. Thanks very much for in advance for anyone's advice.