Differences between shorty and longtube headers?

[Apathy]

WHat are the noticeable differences between long and shorty headers... in say a 2004 GT... ? Sound, performance.. Power band changes... etc?

[DropTopStang]

In my experiences, long tubes sound better...they have a more aggressive tone and i've never been in a car with l/t's but from what I have read on here, they yield higher HP and Torque numbers

Shorties will change the exhaust tone some and will give you a small boost in hp

[Apathy]

I was reading up on long headers.. and apparently, there is concern that you might fail emissions, even with cats, is this common?

[TheGreekGuy]

good question. i think its because even tho you have cats they can still be tampered with because they are not from the factory.

[Mustang Bill Jr]

It depends on what your state does for testing...

Connecticut plugs in to you OBD2 port for testing and as long as you don't have any engine codes your good to go... My buddy doesn't have cats so all he had to do was get an SCT tuner, turn off his mils so there wasn't any check engine codes and he had no problems.