^Read the link below, they are a forum sponsor. As far as preventative measures for a car, this one has probably by far the biggest reward should there be a problem.
The one problem with waiting for the clutch to go is that your driving style can add a few extra years to the life of the clutch and push you past the break point on the IMS failure (if you are in fact in that small danger pool). If I'm not mistaken 'most' of the failures have occurred after 70K miles. But it's not unheard for it to happen well before then....
p.s. If you have a December 2008 issue of Excellence they discuss the procedure and there is a more in depth article coming out later in the year.
http://flat6innovations.com/saving-an-engine-ims-retrofit
I love this picture