[v8Toilet]

I've done dyno testing of JBA headers and a Spintech muffler using the stock pipes and also the SSautochrome headers with a Gibson muffler I believe (have to check that to be sure). I used to have them posted on TS but TS erased them and now I can't reload them because they put a ridiculously small file size limit on them. I can tell you that based on my dyno testing that this combination makes great low and mid range torque gains.

The Gibson headers are very similar to the SSautochrome headers and JBA headers so my guess would be that they make about the same gains. I also have dyno graphs of the SSautochrome headers too compared side by side with the JBA headers and they are very close with the JBA headers having a very slight advantage. The JBA and SSautochrome headers are stainless steel so if you opted to get the Gibson headers just make sure they are stainless steel and not mild steel.

I think most people just don't bother with Gibson because the JBA and SSautochrome headers are proven designs here on TS and no one wants to be the first. The SSautochrome headers can also be bought for as little as $150 brand new so they are hard to beat.