ls rattling intake

I just got my new ls and i noticed that there is a weird rattling rolling type noise coming from the intake that gets much worse when put into gear. It seems to go away when given any gas. Any ideas

You sure it't the intake? I'd put it down to the exhaust. Check for loose heat shields. I had a couple screws come loose several years ago that caused a rattle similar to what you describe. Check the entire length of the exhaust for any clearances less than 1/2". I also had a rattle from the tips tapping the rear valance. That rattle would happen over bumps, especially in reverse.