Ok….school me on headers on an LS3 base, no other mods. I want to use cats and keep my NPP mufflers. If I can get away without spending Kooks money, that’d be the ticket. So questions:
* Size recommendations?
* Ceramic, heat wrap, or none….pros/cons?
* Avoiding idiot lights….using all O2 …is this a hassle? I see guys removing 2.
* Cats.. Can I use stock or do I have to buy new?
* Expected HP gain?
* Ideas on what I can expect on instal cost?

Appreciated!

 

And X pipe or H pipe. Seems like I’d be after low end torque so H pipe?

 

I'm using American Racing 1-⅞" headers (catted). Did not coat as I love the look of coloring of the headers. You will need harness extensions for the 02 sensors. Also would recommend a starter heat wrap. I went with DEI starter heat wrap and seems to work well. I'm also using factory NPP exhaust and I love the sound of the combination. As for HP gains I don't know because I didn't have a base dyno done before installing. After work was performed it dyno'd at 414 hp to the wheels on a Mustang dyno. That was just with headers, and a Ram Air SS intake.

• ARH $2,300
• 02 Extension Harness not sure because they were included in the box with my headers.
• DEI starter heat shield $30

As for the header size I went with 1-⅞" because I intended to add a super charger in the future. While I no longer plan to, at least I have the headers size correct if I decide to go back to that idea in the future. If you're just adding headers with no plan for other mods, 1-¾" headers would work just fine. The biggest issue I see is the headers do add plenty of heat under the hood. So coating, or wrapping could help, especially if you live in a place with brutal summers like around the Houston, TX area.

 

Here is a video of my GS coming off the rack after an alignment. Should give you an idea of sound with catted headers, and NPP exhaust with valve open.