I changed mine at 120k ... well because it failed on me.
Shame on me.
Luckily for me, it only jumped a couple of teeth and didn't damage the valves.
I do recommend changing it between 95K and 105K or before these times.
Hatch Nation Member: #147
R.I.P - FELLOW FF MEMBER, IZZY, BLK2k3GTS, will always be remembered. We will compete on a different course again one day.