Changing it isn't all that hard. A lot of PB blaster on the 2 rear studs. Cut off and replace the 4 bolts down by the cat, and out it comes from the bottom.

Here'* a better video. You can hear it loud and clear in this video.

http://www.youtube.com/watch?v=3ABo2vAfTIY

I have a WOT 0-45 (redline) video uploading so you can hear what that sounds like.

Here'* the WOT video.

http://www.youtube.com/watch?v=SzmehXfRbIw

I could hear no tick on the WOT video. I can hear it good on the other. I'm still going with exhaust tick

I hate to say it, but I am not convinced it is exhaust. It sounds mechanical in nature. Exhaust ticks are usually pretty regular, and easily reproduced under the right circumstances. I couldn't begin to tell you what it is though.

If it is something else, I would like to know what. A valve train tick should be there all the time. A spun bearing will be more of a knock instead of a tick. I've heard exhaust leaks and ticks sound like that. however, a video over the internet makes it hard to say for sure.

Did the timing cover come off at any point? Any idea what side of the engine the noise is coming from? I am sure you can see where I am going with this...

Hmm, timing chain tensioner.

Actually, that might be it, because it is really bad at a specific rpm it seems like. Kinda envisioned a chain flopping around, that is why I asked.

How many miles on that valve train?