ok... so! I have nailed it down to it IS in fact, the CAI. It's coming from up front left and it happens right after that "whoosh" of air sound when things "kick in" and it stays constant until I let off the gas.
I have a videos here of the sound. Check it out!
https://www.dropbox.com/sh/76irt1s0q5y3byx/AAB-0XUPzo3LUkMtqzyvhRo6a?dl=0
I called S&B and they were VERY helpful. He said, I need to first disconnect the battery again and let it sit for a full 2hrs to ensure everything resets. (I doubt this is the issue, but I'll do it)
He also said, that it sounds like something is not secure and/or that because of something not being secure I have collapsed the air filter. Most common non-secure thing is the main inlet right there over the top of the radiator. It's held down by two plastic rivets and there's that rubber grommet thing there. That WAS a huge as pain to get back into place for me for some reason. He said if that's not seated down perfectly this can happen. So we'll see. Said it is the CAI and that it should not be doing that.
I travel for work and am without the truck until I get home Friday eve. So.... until then! Ugh....
More to come!