'99-'01 Headers fit '03?

[Roush97]

I know that the '01s have smaller exhaust ports but is it so much different that putting 01 headers on an 03 will be worse than keeping the stock logs? Has anyone done this and have some dyno gains to post?

 

[Roush97]

ttt

 

[cobrabruce]

Here is a picture of a stock '03 exhaust gasket on top of a stock '99 gasket. As you can see there is a considerable difference. Personally, I would not go through the hassle of installing headers if I did not have the correct ones. Like you say in your sig "If you ain't gonna do it right, then don't do it at all"!

 

[Silver 03 Cobra]

From what I've seen, 99/01 BBK LT's are putting out about the same power as 03 specific headers. Uncle Meat and I run 99/01 JBA's and I'm making 484 rwhp and 525 rwt with mine without the chiller. I don't think there are too many 03's making much more power than that with similar mods. My 03 ran the fastest pass at FFW in VA running against a lot of 03's with Kooks and JBA's.

 

[hardhit99]

Originally posted by Roush97
I know that the '01s have smaller exhaust ports but is it so much different that putting 01 headers on an 03 will be worse than keeping the stock logs? Has anyone done this and have some dyno gains to post?

i have heard a few people going with the 99 01 headers without problems or low power gains, but personally i would be more confortable with the 03 headers. It's a big mod, and like said above, why not do it right.

 

[Silver 03 Cobra]

The gains with Kooks are identical to BBK's. There has been a lot of stuff put on the 03 Cobra specific market that boasted big gains or non-slip or whatever only to find out that it isn't so. My full exhaust is 99/01 from the headers to the tips and it's definatley done right. The ports on the 99/01's are not smaller. The corner radii are bigger and that reduces area slightly. That's all. The rectangular dimensions are the same. In fact, with the method JBA welds inside their tubes and the undercut from the weld, the JBA's match up pretty close. If you have money to burn, then go ahead. There have been a lot of reports with clearance problems on Kooks and I just talked to a guy that had problems with his Bassani mid-lengths. I'll stick with something that's been on the market for awhile and is proven.

 

[shetheri]

I agree completely w/Silver. There are a lot of products on the market that state they are 03 specific and they are not any better or different than the 99/01 Cobra stuff. They are just more expensive and less proven.

Scott

 

[Roush97]

Thanks for all the information guys. Its outrageous how much more money they are trying to get for the 03 specific one compared to the 99-01; its almost double the price. I want to put headers on now because I have the engine out of the car so it would be a lot easier than doing it later. I want to go with shorties if I can find some for the right price as I already have a Bassani x. Thanks guys.