I took a look on the gibson website and they now offer headers for the 3.9 motor for those who are interested.

 

do you have them on your truck? I just put headers on my 3.9 and WITH my programmer I only got a 10 horse gain. What does Gibson claim?

 

I'd bet most of your gains came from the programmer, the headers are gonna need a free flowing exhaust and good intake setup to see the bennifits of it. do you have a pic of your airaid intake you can post? If i recall, it doesnt have a shield and draws air in from infront of the motor. if that's the setup, it sucks. you need to funnel in outside engine compartment air into your air filter. that alone will give you some free ponies for sure. another thing, on your air filter, you can adjust the size of it and have your power band shift a little. On my Ram (which is where I spend the bux) I've got 2 filters, 1 being the stock cone that came with the intake kit, and the other being the 7x9" filter. the big filter will definately let the motor pull harder up top, but it'll loose some low end.



oh, I just read your sig... how is your exhaust setup? single in/out...etc... and if you can post a pic of your intake setup. I'll bet we can make it perform better... (been there/done that on my truck already).