Hi I am going to put headers and a dual exhaust on my 76 f150 4x4 w/390 and 4spd. I plan on using Hedman headers and 2.50" tubing with Glasspacks. my first question is would 2.25" be better and has anyone used the Hedman headers with this combination and if so how was the fit. Any feedback would be helpfull.

 

If the motor is stock, I would use the 2.25' exhaust to keep a little backpressure for torque.

 

other than a performer intake and 750 carb which is to big for the engine it is stock.

 

750 carb?????????????????? why. is it a mechainical secondarie carb or vacuum? that carb is a poor choice in a truck if it is a non vacuum secondarie

 

Yea it was a poor choice made before I owned the truck. The carb is a Edlebrock performer #1411.

 

as far as the 2.50 pipe it's really a matter of the good old "Bigger is Better" idea that for some reason people believe. If you want that big look go for it, but as far as power it's not going to help you one bit, like he said the extra back pressure will give you a very small increase in torque but neither is going to be verry noticable. And even if you are going for a loud exhuast my suggestion would be to play with the glass pack size instead of the pipe. I would stick with the 2.25 and besides it's easier for us exhuast tech's to handle. (that 2.50 is heavy) if you have any more questions let me know this is what i do every day.

 

hey thanks O4k for that. The other question I have is would it be wise to pay the extra for what I am told are flex couplers? They use a stainless steel braid to let the exhaust move up near the header. The reason I ask is because who ever did the exhaust last time did not take into account that the the front driveshaft moves as the suspension cycles and while off roading I managed to hit the exhaust up near the manifold with my front u-joint. Thanks again.

 

well the flex pipe is really expensive and as it might withstand a hit from the u-joint a couple of time's it will end up getting torn apart. My suggestion without looking at the exhaust myself is to ask your local shop to move the pipe so it will clear. most shops will be able to bend there own pipe making it easy to customize. flex pipe is mostly used for 4 cyl smaller vehicles that tend to vibrate a-lot which causes the exhuast manifold or the pipe itself to crack. they will install a small section of the flex pipe in order to let the exhaust have some give to it.

 

I have Hedman Hedders on my truck. They are the fenderwell type. I used 2 1/4 pipe and glasspacks, long ones (I think 33").

I like the way it sounds just driving around but it is too loud when I am getting on it, and towing a TT I do that a lot.

When I first went from the factory single exhaust with a catalyic converter and went to the hedders and turbo mufflers, I got zero gain in gas mileage and zero gain in power. I was quite surprised.

I have replaced the hedders and exhaust 4 times. Next time, if there is one, I will put the original exhaust manifolds back on and do a single 3" pipe and a flowmaster muffler.

 

I put the headers on early this week and I have 1 issue with them. One of the primary tubes is about 1/16 of an inch from my starter. I hope this does not cause any starter problems. I called Hedman and they gave me a part number for a heat shield from a sister company Transdapt or Transadapt. Anyway I have the front suspension out of it right now for a 4" lift and a conversion to 78 steering. I for some reason thought it would cost around 150.00 for midas to weld up my exhaust system but turns out they want 250.00 even though i have the mufflers. Does this price sould right or should I try a smaller shop?

 

I installed headers myself (PITA!) and took my own turbo mufflers to the shop. Got true duals 2.25'' mandrel bent and both exiting in front of the passenger tire for $150. If I had gone with rear exits it would have been more like $200-250.
Shop around. I had quotes as high as $300 and some places refused to use my mufflers.
My headers miss the starter by about 3/4'' and I've had no problems so far.

 

That answered my question, I was wondering if the headers helped the mpg enough to make it worth the money.

 

something to keep in mind when pricing an exhaust job is that you will more than likely save money if you have that shop order the mufflers you want rather than bringing your own. most shops will ad about 20% to the total when you bring your own mufflers. $250.00 isnt terrible but it could be better. my dual exhaust job is generally $300.00 and that is from the manifold (or hedder) all the way back with glasspacks or mufflers. (flowmasters are generally a little extra)

 

(also keep in mind the placement of the exhaust, pipes that go all the way to the bumper cost more than those that go to a fender.)