Have fun getting the OEM fan off, it was a PITA. My bolts were a bit rusted, and took some "coaxing" to get off. Needless to say, some bloody knuckles, a bit of cursing 30-45 minutes of my time and I was done. Having said that, I also have a Injen intake, so no factory airbox and piping to get in the way. That made it a bit easier. You made need to add some time to that if you have to take that out, which is another 20 min for removal and install.