Read my thread?
Safely Modding Your 3800.
Get at it if you haven't, its in my signature.
To T0pwater...when you upgrade to a GenV unless you are cammed or have a full size intercooler...you are in no way needing anything more than a ported factory throttle body. As for the 180* T-Stat...it makes a huge difference after you get a tuned PCM since the fan turn on point is lower. Putting it in a stock car won't net anything besides lower crusing temps on the highway and crappier MPG's