Well gang, believe it or not I do NOT have the S&S headers.

The 98-00 LS400 manifolds are longer and the cat flanges are rotated relative to the GS400 manifolds that the S&S headers were designed to directly replace.

My set of headers is currently at Jet Hot and should be in my hands in about 2 weeks. I have decided to modify the headers rather than the Y pipe. This keeps the car serviceable with factory parts at any time. I will also be creating a new Y pipe but it will be a direct bolt in fit to the factory.

Modifying the headers requires that I jig the stock manifolds, cut the cat flange off the S&S headers, extend and re-weld the then extended flange in the correct position for the factory installation.

By doing this I will have the ability to modify headers (by request and arrangement) for any one else that is interested in this same approach.

I will also post pictures and progress as I move through this project.

The headers should generate the same HP and TQ increases that the GS400s see roughly 15-20 RWHP and RWTQ and improving engine response, power under the curve, feel and the fun factor.

For a Y pipe upgrade I plan on building a direct bolt in replacement that will replace the stocker which unlike the GS has a bottleneck resonator and ugly cut and slash sections at the cat outlets. The plan is a part that will be a direct replacement. I also plan on a second Y pipe that will replace the center muffler section and bolt in and use the stock rear mufflers. These parts will give a number of options for power and noise levels. I will build them to suit my taste for relatively quiet operation, preserving low end power/torque and allowing peak possible power/torque.

Depending on how hard this project turns out to be I may consider making other copies.

Stay tuned.

 

wooohooo jbrady always giving the LS guys some fun .

are there any other places that i can get the S&S headers other than l-tuned?? and are they all at $699?

 

good stuff, any estimate on total final cost incl. the modifications and the cost of the headers?

 

Yeah, you can find them both in the classifieds, and from a few other distributors. I passed up a new in box set, for $550 shipped, but this was when I bought my LS4, so I had to pass it up.

JBrady, like PD asked, can you possibly give us a breakdown of what the shop cost to do this?

 

o h thanks ofr response, im gonna get s&sn heaeders when i put in a mew moto r for my car...sjust wondering where to geit to from.

 

I've never seen pics of headers on the 98-00. Post some pics of the build, just got to see the clearance.

 

jbrady,
Any updates?
I'm want headers for my 99 LS California car!

I don't care about CARB approval, I just want it to pass the sniffer test.