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  1. #1
    FEP Senior Member Sask84gt's Avatar
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    Default Opinions on header/exhaust set up for 84gt

    Hey all, looking for recommendations on headers and exhaust for my 84gt. We are putting a 302 roller motor from a 91 gt in it. Plan to upgrade the intake and carb but for now the rest will be stock. What's a good reasonable priced set up that sounds good?

    Thanks
    Last edited by Sask84gt; 04-21-2018 at 08:48 PM.

  2. #2

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    You looking for long tube or shorties? Going to do a true dual exhaust or keep the factory arrangement? How much are you looking to spend?

    Jess
    Previously owned;
    1979 Mustang, v6 swapped to EFI 393, custom installed m122 blower, 4r70w trans, Megasquirt II, T-top swaped in.
    1990 Mustang, 545 BBF, C-4 with brake, ladder bars.
    1983 Mustang, 1984 SVO Mustang
    1984 Mustang convertible, v6 swapped to 351
    1986 Mustang GT, 1989 Mustang GT convertible
    1992 Mustang coupe, 4 swapped to 302

  3. #3
    FEP Senior Member Sask84gt's Avatar
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    Quote Originally Posted by Mustang-junky View Post
    You looking for long tube or shorties? Going to do a true dual exhaust or keep the factory arrangement? How much are you looking to spend?

    Jess
    What's the difference between long tubes and shorties? Probably do true dual exhaust. Price I'm not sure about cause I really have no idea what this stuff costs. Newbie

  4. #4

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    Some things to think about... Putting duals on requires a new transmission mount bracket (not expensive) and rerouting of both the fuel and rear axle brake line. Fitment of headers can be tough (steering knuckle) and if you stick with the single your old y pipe will need to be modded due to the exhaust bypass whatsit on the passenger side. I posted quite a bit of my experience with this in a thread in the gt350 section http://vb.foureyedpride.com/showthre...e-with-exhaust

  5. #5
    FEP Senior Member Sask84gt's Avatar
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    Quote Originally Posted by emerygt350 View Post
    Some things to think about... Putting duals on requires a new transmission mount bracket (not expensive) and rerouting of both the fuel and rear axle brake line. Fitment of headers can be tough (steering knuckle) and if you stick with the single your old y pipe will need to be modded due to the exhaust bypass whatsit on the passenger side. I posted quite a bit of my experience with this in a thread in the gt350 section http://vb.foureyedpride.com/showthre...e-with-exhaust
    Thanks for the info. Reading a bit of your thread I noticed that your true dual exhaust setup you got did not require rerouting fuel and brake lines. Is it only certain brands or types that you need to do this or is it because you have a gt350 and it has cfi?

  6. #6

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    Well... Although my guys did a very good job of routing the exhaust and I am good with it, I am going to take others advice and not suggest anyone else go that route since I can't guarantee your guy or you won't cut it too close. Up in flames or no brakes isn't something I want to be responsible for. Yesterday I even put some reflective heat tape on the brake lines on the driverside of the engine compartment as I felt all the heat from the headers might be unhealthy. Couldn't hurt. I will say that the hooker headers I have, although they get warm, fit quite well and since the rebuild my engine is running nice and cool and the engine compartment is far far cooler than it used to be. Almost scared it is running too cool.

  7. #7

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    Quote Originally Posted by Sask84gt View Post
    What's the difference between long tubes and shorties? Probably do true dual exhaust. Price I'm not sure about cause I really have no idea what this stuff costs. Newbie
    Shorties are a tubular version of a stock exhaust manifold. Collector is usually in the same place so factory pieces after the manifold will bolt on. Long tubes the primary tubes are longer and frequently equal length(both good for power). Collector is back by the transmission. Shorties are easier to install. Long tubes are harder to install but will usually give more power. How much depends on the application. If your car is pretty much just a mild bolt on shorties would probably be the way to go. I like a true dual exhaust, but it will involve more stuff when you get back near the rear axle, unless you don't run tailpipes. I prefer tailpipes though, worth the extra effort not having to deal with the interior noise that comes with running dumps. The internet is full of short verses long tube header info, do some looking around. You could probably find some videos on YouTube to give you an idea of what different combos sound like.

    Jess
    Previously owned;
    1979 Mustang, v6 swapped to EFI 393, custom installed m122 blower, 4r70w trans, Megasquirt II, T-top swaped in.
    1990 Mustang, 545 BBF, C-4 with brake, ladder bars.
    1983 Mustang, 1984 SVO Mustang
    1984 Mustang convertible, v6 swapped to 351
    1986 Mustang GT, 1989 Mustang GT convertible
    1992 Mustang coupe, 4 swapped to 302

  8. #8
    FEP Senior Member Sask84gt's Avatar
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    Quote Originally Posted by Mustang-junky View Post
    Shorties are a tubular version of a stock exhaust manifold. Collector is usually in the same place so factory pieces after the manifold will bolt on. Long tubes the primary tubes are longer and frequently equal length(both good for power). Collector is back by the transmission. Shorties are easier to install. Long tubes are harder to install but will usually give more power. How much depends on the application. If your car is pretty much just a mild bolt on shorties would probably be the way to go. I like a true dual exhaust, but it will involve more stuff when you get back near the rear axle, unless you don't run tailpipes. I prefer tailpipes though, worth the extra effort not having to deal with the interior noise that comes with running dumps. The internet is full of short verses long tube header info, do some looking around. You could probably find some videos on YouTube to give you an idea of what different combos sound like.

    Jess
    Thanks Jess, have been doing some reading this afternoon. I'm thinking of going equal length bbk shorties to H-pipe. I'd like to do catless but not 100% sure yet.

  9. #9
    FEP Super Member sowaxeman's Avatar
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    Just beware if you go cat-less, the exhaust is going to be rather obnoxious in terms of smell. You don't say weather your car is a hard-top or 'vert, but if it is a 'vert you will probably hate the smell, and how your clothes smell after you park the car. If you are a hard top...well you won't hate the smell as much as the people behind you
    Jason Smith
    MCA #65481

    '82 Capri RS Resto-Mod
    '88 #400 Saleen Coupe "Mean Machine" Legal Guardian
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  10. #10

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    Obnoxious is the smell behind most "catted" vehicles, where the nasal assault is a stink like a large amount of perm solution spilled in a hair salon... ridiculous stank that's downright offensive. Any non-cat/s stink is about inefficient, fuel-wasting, wrongly-ignited internal combustion malfunction, not a catalytic converter deficiency.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  11. #11
    FEP Senior Member Sask84gt's Avatar
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    Hmmm, I'm not sure what to do lol. My car is a t-top car so if it does smell I'm going to smell it. Ive been in my brothers 600hp cuda that's catless and have not really noticed anything bad. I mean it smells but it's a muscle car lol

  12. #12

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    I've never noticed a smell when not running cats. Unless maybe your tune was way off. Of course I don't spend much time sniffing the back end of my cars.

    Just a heads up, equal length shorty headers are notoriously a pain in the butt to install and route spark plug wires.

    Jess
    Previously owned;
    1979 Mustang, v6 swapped to EFI 393, custom installed m122 blower, 4r70w trans, Megasquirt II, T-top swaped in.
    1990 Mustang, 545 BBF, C-4 with brake, ladder bars.
    1983 Mustang, 1984 SVO Mustang
    1984 Mustang convertible, v6 swapped to 351
    1986 Mustang GT, 1989 Mustang GT convertible
    1992 Mustang coupe, 4 swapped to 302

  13. #13
    FEP Senior Member Sask84gt's Avatar
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    Default

    Quote Originally Posted by Mustang-junky View Post
    I've never noticed a smell when not running cats. Unless maybe your tune was way off. Of course I don't spend much time sniffing the back end of my cars.

    Just a heads up, equal length shorty headers are notoriously a pain in the butt to install and route spark plug wires.

    Jess
    So what's the benefits of equal length shorties over non equal?

  14. #14

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    Quote Originally Posted by Sask84gt View Post
    ... Ive been in my brothers 600hp cuda that's catless and have not really noticed anything bad. I mean it smells but it's a muscle car lol
    That is a myth that I wish would go away. Muscle car does not have to mean inefficient fuel-swilling stank pig. Very much so the contrary. Muscle should and can/does go hand in hand with efficiency, by definition. I've stood at enough car show entrances/exits, with watering eyes, due to the things not being adjusted or tuned properly at all, AND due to the inefficient, expensive, billet, shiny, swiss cheese too fulla holes inside screwing up function and proper AFR for efficient internal combustion in general, and/or colorful contraptions/excuses for what passes for new/replacement or "new and improved" carburetors today.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  15. #15

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    Quote Originally Posted by Sask84gt View Post
    So what's the benefits of equal length shorties over non equal?
    Scavenging exhaust equally, the whole marketed advantage of exhaust headers... non equals are basically tubular exhaust manifolds, though usually with a bigger inside diameter than exhaust manifolds, so technically better...
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  16. #16

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    FWIW I went with BBK shorty headers and non-catted BBK chambered X pipe on my 1980 cobra. Not the most expensive brand but better than what I had.

    Later I welded in some magnaflow hi-flow cats onto the x-pipe where I could fit them to reduce the exhaust smell in the garage (helped a lot and was pleased with it). Eventually went with walker quiet flow SS mufflers and dual 2.25 tailpipes. I originally had flowmaster 44's and 2.5" tailpipes but the drone at cruise and rumble was way too much for my preference. I also took a die grinder to the welds inside the headers to smooth them out. They looked very restrictive. Apparently others have had this same issue with the BBK stuff as its not the most high end.

    I am probably restricting the flow a bit with the 2.25" tails but the combo I have now seems to be just right. No drone but still sounds pretty good. Adding cats also helped out the drone and noise as well.

    Also recommend upgrading to the stifflers transmission crossmember and getting the proper dual exhaust hanger(s) kit. The stifflers is a nice unit and the pipes fit in nicely. I had to mod the hanger rods on the pipe a bit because I added the cats later. Doing it again I would probably just pay a little more and get the catted pipe etc. All the stuff for an 86 fit my 1980 quite well except for the rear tail hangers where I had to fab up a bracket to make it work.

    I also moved the passenger brake line fitting to the center of the diff. Its a bit of work but just got the proper OEM tee fitting and brake hose for a later model (94 or 95), remounted them, and then run my own custom 3/16 brake lines to the hubs along the axles. Wasn't too bad really. You can buy most of these parts at the different aftermarket suppliers although it adds up.

    Its a bit of work but IMO the dual exhaust is well worth it.

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