hmmm...

Torqflo fan clutch, AutoZone, $94.99 Lifetime warranty...
Isuzu fan clutch from Isuzu, $227.68, (unknown warranty, but ya can't beat lifetime).

This is a classic case of a "No Brainer"

Even if AutoZone didn't honor the lifetime warranty 8 years from now... which is what I'd hope a product with a lifetime warranty would last at least as long as the Factory one has lasted, even if it lasts half as long (4 years) one could buy a secondTorqflo and still spend less than $227.68
And, according to Marlin, it does it's job extremely well.