Hi all. I have a 1993 F-150 with a 302 and the exhaust manifold is cracked. Thinking about put headers on it. Has anyone done this? Do you notice a difference in performance?

 

A short answer, yes and yes, but it depends....

Obviously, a properly designed header will increase exhaust gas scavenging and improve performance, esp. at the upper rpms. Most people would caution that a shorty header does little to improve low and mid rpm power....however, a header, long or short WILL be an improvement over the restrictive stock manifolds, especially if they are cracked and leaking badly!

You may not notice much of a difference on a completely stock truck, but if you have done modifications (intake, cat-back, cam, head work, etc.) the difference will be more discernable.

I got my truck in July and immediately noticed cracked manifolds. The driver's side manifold was cracked completely in two. Besides sounding like a tractor, the truck did not run well, used more fuel, and performed poorly on every front.

After checking with the local Ford dealership and suffering from an extreme case of sticker shock, I decided to look for used manifolds at local junk yards...every single truck I checked had cracked manifolds...usually between the #6 and 7 cylinders and sometimes between the #1 and 2.

Then I got to thinking about headers....

Various manufacturers are making stainless headers for our trucks...However, be prepared to pay upwards of $500 for them...

I went with the Gibson shorty's. $350 (I think) at most online speed shops. Be ware, however, that in my case the swap was not 'bolt-on' like the advertisements state...these headers are designed to accept 2" to 3" pipes...my truck had 1 7/8" pipe, so a temporary reducer was needed to get it buttoned up.

I also had some trouble with the driver's side header...it did not fully clear the motor mount, requiring careful grinding and cutting of the rubber mount to achieve a proper seal.


After all is said and done, however, I am and was very pleased with the product. Gibson headers have a meaty 3/8" flange (will not warp!) and seem to be made fairly well.

A word of warning, however, don't be fooled into thinking that the headers will be 'show quality'. I found many of the welds somewhat sloppy and the chrome plating had some imperfections.

Also, if you go with chrome, be ware that they will blue in a matter of a few minutes. The only way the I've found to remove the bluing is to rub the headers down with a fresh sliced lemon. You'll want to make sure that if you do go with chrome that you stay on top of any rust spots or oxidation that creeps up. Also, I would strongly recommend staying away from header wraps or blankets if you opt for the chrome finish. The chroming process has a way of making steel brittle (hydrogen embrittlement), so unless you want to blow a header pipe, stay away from wraps & blankets.

whew! That being said, if I had to do it all over again, I'd probably look seriously into a set of Doug thorley headers (not sure if they have a fitment for this application) or I'd get Jet-hot coated pieces for a more trouble free finish.

Good luck, let us know how it turns out!

BTW; with the addition of the headers and a rebuilt tranny, my gas mileage increased from 12.5 to about 17 or so...you mileage may vary....

 

Thank for the info. My truck is not getting very good gas. I have been looking for the problem for awhile now. Then I found the crack. I think that I will change to headers and see what happens. Thanks again.

 

You got that much of a mpg increase just from the headers? My tranny is fresh rebuilt, too, and I'm experiencing the 12-13 mpg right now. I might have a crack in one of the manifolds, but I'm not sure (only smell exhaust sometimes). Also does gibson make those in black? I don't need chrome under my hood. I would just like to have some with the thick flanges like yours.

 

I can't say it was all due to the headers...it was more like a combination of headers, running 4 or 5 bottles of fuel injector cleaner thru it, and the tranny breaking in. Other than that, I went from 12.5 to just over 17 mpg. This was with 66,000 miles on the stock plugs, cap, rotor, wires, exhaust system, and an air filter with about 2500 miles on it...I have since replaced all of these and the coil and at last check (yesterday) got 20 mpg on the highway running 65 mph on a 180 mile round-trip to Dallas and back. (With the A/C off)

Keep her tuned up and go easy on the old gal and you'll be surprised!

As for the Gibson headers in black...I'd have to check...I don't know that there is such an animal. I stayed away from the black due to rust concerns. (the black tends to burn off, leaving bare metal exposed to the elements) Living anywhere in Texas, the high humidity is a concern for the exhaust system....esp. in the winter with the heat up and rapid cool down in an atmospherically wet environment. If you must get the black ones, keep them wiped down and go over them with fine steel wool if they start to rust...then save up and get 'em jet-hot coated.

And unless you're real handy with the grinder and ready to get real p.o.'ed, I'd consider having a shop put 'em on. Should cost $90 to $100 for the install.

Keep us posted.

 

Long tube headers are usually prefereable for the trucks. More torque.

 

I have a 95 f-150 thatI put shorrtys on It gave it a little better low end torqk And about 2-3 mpg better. and they were easy to install

 

Before I installed my Hooker LTs I used to run some shorty headers from a 5.0 Mustang. The results were lackluster. I got a bit better pull from about 3000rpm+ and a better WOT sound. That's about it.

I tossed them aside for the Hooker's I have currently and never looked back. I picked up a very noticable amount of bottom end TQ from idle to 2800rpm and the topend pulls the same.

That's where LTs help... with their scavenging over a shorty header.

So if you're just needing a cheap replacement for a cracked manifold... go with some mkay shorty headers. Get good gaskets and bolts with lockwashers and be on your way.

 

I put headers on my truck they are Flow tech and they where a bout $230 from Canadian tire because both my manifolds where broken in two but my truck would still light them up 5.8 EFI with c-6

 

I started with the same problem, cracked manifold, and went with BBK ceramic coated shorty headers. They are a couple years old now and look as good as they did when I took em' outta the box. Nice increase in performance but I had previously built the engine, slight head mods, crane cam, etc. the difference may have been the stock manifolds were holding me up due to the engine build. My mpg didn't increase but by about .5mpg.

If you want power though, long tubes are the way to go.

 

If any of the 300 I-6 boys need them, CliffordPerformance has a lot of nice one's for all of ford's inline sixes.