ok i just signed up for this site not to long ago and find it very helpful. is it me or do they not make a set of long tube headers for a 4.6 03 f150? ive been searching high and low and only saw some shorties, are the shorties even worth it? also i was looking into getting two high flows, but i saw that i might be getting CEL? and with the high flows will i get a drop in MPG and lose bottom end? im trying to get a bit more power without breaking the budget. if you guys have part #'s that would be great! THANKS!

 

No shortys are not worth it, unless your original manifolds are very aged and you have belief that they could crack sometime its not worth getting shortys. Longtube is the best way to go, full performance. 5.4L headers will fit your 4.6L. The 5.4L is mostly a bored out 4.6 remember, so the header bolt ups are exact. Magnaflow offers great converters. Part #s 94306, 94006, and 94106 will all work on your truck. You will not get a CEL as long as the rear O2s are mounted after the hi-flow converters ( and your O2s aren't over 100k miles in some cases ).

Dynatech is probably the best choice for you, you can get Dynatech LTs with 94306 cats mounted on them for $1200.

 

i thought high flows increased my mpg a lil bit. So far they are prolly the best thing i put on my truck because of the very noticable sound increase.

 

ill look into the dynatech. what are teh differences between the hi flows posted above? also, i replace the 4 stock cats with 2 high flows correcT?

 

Yes two hi-flows replaced all 4 factory cats.

94306 is a calmer cat that gives a great deep note to it, and is polished stainless. 94006 is a hair louder version of the 94306 and not polished, still stainless though. 94106 is the loudest one to chose from, its 3"s shorter than the others ( 9"s length to the others 12" ) They will really give the cat-less sound and keep the CEL out.

 

thanks darren! ill be buying the 94106. i was looking into the dynatechs but looks like they only make it for the 5.4. i am kinda screwed if they dont fit cause those are some money. anyone on here put long tubes on a 03 4.6?!

 

Pacesetter makes full length headers. Go to summitracing.com and look them up. They are about 450 for ceramic coated. 300 for painted.

 

thanks i just checked em out on there. i might have to get those pacesetters matched with some hi flow mags. only thing its hard to find a shop down here in CA to install the high flows. the reliable muffler shop i go to wont, cause i wanted to straight pipe my old ride and said they couldnt. the shops that can install it i dont trust their work.