i went to a shop the other day, im friends with the owner. we starting talkin about mods im planning to do since theyre doing all the work, getting the gears i got put in for 250! i told him i was thinking about headers and high flow cats. he tells me its not worth the money id be spending for the power gains. he says that the stock manifolds on our cars flow good and if i just get high flow cats ill see a huge improvment. now i trust him since he just lost the money from the install and hes a good guy. hes done all the work on my buddys stang. what do you guys think, he said hed do it if i wanted to be advised against it. should i?

 

Our tubes flow pretty good. In the old days, we used to get 10-15 hp out of headers but not anymore.

 

I got them for the sound!!! [8D]

 

from my headers and o/r x pipe i got 20 rwhp. they cost me 750. i think what your friend issaying is for the money you could get more from say CAI/tune. just removing the cats will get you 5 hp.IMO headers ando/r midpipe are worth it, plus it sounds much better.so 20 hp plus better sound is worth 750 or even 1200, what the top of the line headers and midpipe would cost.

 

i have a cai & tune already. hes telling me to wait utnill i get the blower to do the headers.

 

I got mine for the sound/future F/I (should have the bottle coming in around 2 weeks)

It gave me a little boost. Not much, but every little bit helps.

 

I definately gained torque with my BBK shorty "tuned length" headers. Its possible that its only because it helped control the backpressure better whick was lost with SLP loudmouths. But either way it helped.

And gave a nice glub glub glub pulsed sound also...

But in the end it depends on how much $$$ you can spare without cringing.

 

You won't see notciable gains until you go F/I. I got mine for the sound, plus I'm looking to add a turbo in the near future.

 

I disagree completely. The stock manifolds are just about the only restriction in the stock exhaust. LT Headers are good for 10-15. High flow cats over stocks are worth nothing, the stock cats flow very well. If you went to O/R h maybe 2-3 hp, O/R X maybe 5.

 

I would compare them to the old 289 HiPo manifold vs the stock 289 manifold. One was a huge improvement over the stock, but not worth it to get headers if you had the HiPos. I feel the manifold of the 4.6 is flowy, sure, not as good as open headers but pretty good on it's own.