Originally Posted by christian370z

From what I've seen, gains are varied with the Stillen headers. Most of the gains are around 5rwhp or so with a few around 10rwhp gained with full intake and exhaust setups. Torque doesn't move much though. Most of the posts I have read from people who had experience with the Stillen headers said it is not worth it unless you find them for a very good price online. They are also much easier to install than LTHs which is a bonus, plus they sound good!

If you are going for max peak HP/TQ, go for the 2nd option. If you want to gain more of a balance in HP/TQ, the last option will be best. I personally have the first option and have 320rwhp/263wtq which is plenty for me, I might get a more aggressive tune later and see if I can get a bit more.