I'm trying to make up my mind on what kind of headers I should get. 4.6L 4x4 01' XLTScrew. So far all the ones that I'm looking at say:

"Not Legal For Sale Or Use On Pollution Controlled Engines, Legal Only For Racing, Not For Highway Use"

AND

"50-State Legal, C.A.R.B. E.O. #D-439-5, Not Legal For Use On Catalyst-Equipped Vehicles Except For Racing Vehicles Which May Not Be Operated On A Highway, Pre-Catalyst Vehicles Must Use Original Emission Control Devices, It Is The Responsibility Of The Customer To Reinstall These Devices On The Vehicle"

What's the harm if they displace heat better than OEM pipes?

Anyone have any installed?

 

They are frowned upon the emissions and such due to the loudness they produce, and help pollution escape the block much faster than with manifolds. The power, and sound gain is very well worth it though.

 

I had some JBA headers installed on my 5.4l and it cost me. I found it made no differance in power but made it sound a little deeper in sound. Then about 20,000 KM later the paper gaskets provided with the headers started to leek. My opioion would be to save your money for a supercharger. Thats the olny way to get real power out of these fords. If you insist in buying headers made sure you buy copper gaskets and nothing else or you will have toubles. Well i did anyway!
Good luck!

 

The only headers that will help your power is the long tube headers! Shortys are a wast of time and money!
Some of the guys on here are running Pacesetter long tubes for a 5.4 on there 4.6 without any problems.
It's hard to find any long tubes for a 4.6

Iv been using stock Ford exhaust manifold gaskets with no leaks for sometime now!

Phil