i'm not exactly sure, but the article said something about the itr having a standard cai? so no. i'm not sure...it's been a while since i've read it. as to whether or not it fits, i have no idea. anyone?
The Type R header WILL fit your LS... but it won't give you the gains your probably looking for... Unless it is the JDM ITR header of course, which has a 2.5" collector... Depending on what kind of cash you are will to put into a header, I would recommend a Vibrant 4-1 Stainless steel header with 2.5" collector... and about the intake, search through the articles, there is a good one on intakes.