Hi all, i've been lurking here ever since I bought my 07 GXP a week or so ago. I'm trying to plan out the upgrades that I'm eventually gonna do to her and I have a few questions. First is about the exhaust. It's either headers OR a downpipe such as the DP7S or DP5S, right? Also, some people are saying that the DP7S with high flow cat is really not much of an improvement over stock, is this true? Also, the shift kits...will doing one of these help prolong the life of my tranny, or would I be better off going with a kit such as the one below? I'm a little confused as to weather or not that is just a do it yourself TEP build. Can anyone with a complete exhaust build and/tranny build chime in please? Finally, I know this last question might be in the wrong part of the forum, but as far as headlights go, are those SPYDER ones crap like I have heard? Would I be better off going with the HID upgrade? Thanks in advance guys.
4T65E High Performance Complete Kit 2003+ GM application