Has anyone installed them on their truck? What gains usually are seen with them? Are they great quality?

 

I think those are the Dynatech Supermaxx headers, I've had them for about 9 months and my only complaint is that the passenger side header is too close to the frame. Search and you will find other posts on this. The first pass. side was hitting constantly and they sent me out a replacement and it is till too close. It was about 1/4" away from the frame when installed and now I bet less than 1/8". It hits every once in a while when the motor torques enough.

I dont like giving this header system a bad review because they are very high quality and I did notice a good power increase even with the stock muffler, however there clearances on that pass. side are not good.

 

Actually they are different (they have them at thunderracing.com) thanks for the post, I'll look into the dynatechs also.

 

Check into the AZSM long tubes,or Togs money well spent on either.