Headers

I have JBA Long Tube headers. I originally paired them with a Banks Monster 3" cat back and left everything else stock. (2 cats and mid y pipe). Which was smaller pipe then everything else) Took it to the dyno shop and initial test showed 180hp @ 5100rpm and 244tq @ 4900. When I left they had me at 244hp @ 4900rpm and 308tq @ 2100rpm. What a difference! Then I decided to change everything except the headers because I was having issues with leaking between the headers and the y pipe. Plus all of it was different size pipes. So I did custom 2.5" pipes from the headers, into a magnaflow x-muffler, split into dual exhaust. Had to put on 2 vibrant resonators cause the cops told me it was too loud. It was a very sharp brap at high rmps when I hammered down on it. Now I have constant 2.5" flow front to back. Took back to dyno shop and had them redo the tune. Now it's 252hp @ 4900rpm and 328tq @ 2100rpm. I also have k&n cold air intake, 3" lift, and 33" tires. My gas milage is terrible when towing my 3500lb trailer, but everyday driving without load I still get close to 500kms. All in all I am happy. But this leads me back to the headers. I've had them now for 27 months and one has cracked. Anyone happen to know what their warranty is?