Does anyone know if the 2003 4.6l and 5.4l v8 engines have the same exhaust manifolds. They seem to have the same part numbers on the ford website and if so will long tube headers for a 5.4l fit on a 4.6l?? I am asking this because i cannot find long tube headers that will fit a 4.6l everything is for the 5.4l.

 

Not sure about that. Did you check with Pace Setter and/or Stainless Works for 4.6L applications?

 

I have been looking into this myself, if you find out any info let me know

 

i have looked every where i have contacted pacesetter and obx and neither of them make lontube header for a 2003 4.6l f150. however im starting to wonder if the 2004 4.6l lontubes will fit a 2003 because its the same engine just maybe not the same clearence

 

They are not the same.

 

i used pacesetter 5.4 long tubes on my 2002 4.6. had to remove some material from the trans bellhousing but they fit. i'll look for the part number of what i used.

 

I have a 4.6l 2002 2wd extended cab and have some pacesetter 5.4l longs as well. How much did you have to remove from the bell housing and how much trouble was it to install the passengers side for you? I as well can't find any 4.6l longs so if it will work without having to remove a whole lot i'm going to hang on to them.

 

let em know if you do this and how it works out i really want some long tube headers

 

why not go to a shortie header? those long tubes don't offer much more if any hp in lower-mid rpm where most drive and they also heat the transmission up as well

 

Shortys show no performance gains over stock and longtubes give around 20 hp and ft lbs torque