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86 k5 dual exaust

Discussion in 'The Garage' started by jd70ssclone, Jan 4, 2007.

  1. jd70ssclone

    jd70ssclone 1/2 ton status

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    hey guys i have a 86 k5 blazer with a 305 sbc in it i was wondering if any of u guys know of a dual exuast kit for my truck. i live in maryland do i have to run catlytic converters?also has anyone heard of that stuff you poor into your gas tank and it supposibly makes you pass emissions tests beacuase i really dont want to run cats thanks alot
    josh
     
  2. K-5 Bomber

    K-5 Bomber 1/2 ton status

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    Don't know if this really works or not, but I've heard this trick from a couple of smog guys. Do an oil change and add a detergent. Run that for a couple of days, then drain it. Attach a shop-vac to your filler tube and run that for a good long while (?). Add your oil and take it IMMEDIATELY to your smog shop. Heard from a local guy that his rig would not pass before he did this. On his second try (after doing this) he passed. Now this is CA, but we're in the extreme northeast corner where our smog laws are much less strict so I don't know if this will meet your smog requirements. Worth a shot?
     
  3. Metrodps

    Metrodps Strange but nice guy Premium Member GMOTM Winner Author

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    1. i was wondering if any of u guys know of a dual exhaust kit for my truck?
    A. Yes LMC Truck has one go to http://www.lmctruck.com/icatalog/bzc/0083.html I got the performance turbo system and love them on my 1987 305. We had to cut a little off the front pipes. They have great sound just ask jekquistk5 he has heard mine.

    2. i live in Maryland do i have to run catalytic converters?
    A. Can't help you on that one.

    3. has anyone heard of that stuff you poor into your gas tank and it supposedly makes you pass emissions tests?
    A. Several guys here have posted about it and they claim it does work.
     
  4. badmix

    badmix 1/2 ton status

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    have a custom shop build you one, its super easy and there is plenty of room under. Get some catco cats. Keep the cats. otherwise your exhaust will be raspy and annoying , trust me. Plus the fumes will kill ya worse without them. They dont inhibit power at all.
     
  5. pauly383

    pauly383 Daddy383 Staff Member Moderator

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    Taking the cats off is so Old School opinion , IMHO . The aftermarket and OEM has caught up to emissions , a simple high flow cat , to a dual outlet muffler , with some nice tips makes more sense . Especially if you have a small block .

    My 305 makes plenty of low end power , and cruises the freeway with a 2.5 inch pipes , single cat , and turbo muffler . Had plenty of power for wheeling even when I had 33's and 3.08 gears .
     
  6. 73k5blazer

    73k5blazer Unplug the matrix cable from the back of your head Premium Member

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    Even regular cats these days work fine, no need for a special racing or high-flow version anymore. I bought a replacement cat for my '86 C10, I could see straight through it, just some screens passing thru there, it was 1/8 the weight of the original cat, and about 1/3 the size.
     
  7. dhcomp

    dhcomp 3/4 ton status Premium Member

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    YOu can't run the stuff to eliminate the need for a cat, you'll fail teh visual inspection if there is one.
     
  8. lochenjons

    lochenjons 1/2 ton status

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    I know in ca where smog is way strict you don't have to have cats if they didn't come with the truck from the factory. But '86 probably did have cats so your probably screwed there. I dont have to have cats for my '77 tho
     
  9. Metrodps

    Metrodps Strange but nice guy Premium Member GMOTM Winner Author

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    have a custom shop build you one :laugh:
    OK the custom pipes are the same as what I got from LMC. They are made for the 1973 to 1978 trucks.

    otherwise your exhaust will be raspy and annoying :what:
    My exhaust is neither and sounds like my 1980 Z28 when it was new! I love the way it sounds when you get in it you know it has some guts and has a nice rumble at mid range.

    Plus the fumes will kill ya worse without them :screwy:
    WTH are you smelling? I burn unleaded gas and there is no odor or fumes. Must be a Floor a duh thing. :haha:
     
  10. TripleJ75

    TripleJ75 Registered Member

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    I was always told to dump some "dry gas" in the tank before going thru emissions...

    My 90 Jimmy has the stock cat and a 40 Series Flowmaster with custom bent pipes ($400) sounds great! You don't have to do much to make a Small block sound cool!
     
  11. Metrodps

    Metrodps Strange but nice guy Premium Member GMOTM Winner Author

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    My 87 has GM manifolds and the LMC duals total $239.00 :waytogo:

    Muddybuddy will be hearing mine in a day or two also so there will be another ear on mine. :wink1:
     
  12. TripleJ75

    TripleJ75 Registered Member

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    That is a good deal!
     
  13. jd70ssclone

    jd70ssclone 1/2 ton status

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    hey man thanks alot for the info so you said that you run the lmc dual exaust but in their magazine it shows its only good till 78 beacuse of cat converters and you stated yours is a 87 what did you do about cats???
     
  14. dyeager535

    dyeager535 1 ton status Premium Member

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    It's actually fairly simple.

    Where you live, and the vehicle is registered, are you subject to a visual search? If the answer is yes, you would be required to have a single catalytic converter on the vehicle.

    Depending on how law abiding and environmentally friendly you want to be, it is illegal at the *Federal* level, to tamper with any of the emissions stuff. As this applies to cat converters, you cannot alter the quantity the vehicle originally had, which in your case is one. (these laws apply to the AIR pump you ask about in your other post as well)

    It is usually cheaper/easier/legal to go with a larger single exhaust (like 3") rather than run duals. There is no loss of power by going large single, or enough restriction to worry about with a modern cat converter.
     
  15. beater_k20

    beater_k20 Banned

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    the best solution for you is to become mildly dyslexic... suddenly the 87 is a 78. :haha:
     
  16. Metrodps

    Metrodps Strange but nice guy Premium Member GMOTM Winner Author

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    I AM NAKED and loving it!

    The trucks have not changed that much since then. Much like the 1980 Camaro to the 1974. You have to do a little donut flange cut off on pipes turning them into a compression fitting. If you want cats just cut pipes before mufflers and add them in. Where I live we do not have inspections.

    Yes I care about the earth but WTF get a life... If you are that worried about it sell your vehicles and get a treadway. Al Gore said the biggest damage to the environment is the auto! SO no matter what it is bad.

    They now say that the ozone is in a natural cycle and that cows produce more dangerous gasses than cars. NO matter what you do someone will be unhappy. If I wanted performance I would of got a Lamborghini!! My truck is twenty years old and in most area exempt any way.
     
  17. beater_k20

    beater_k20 Banned

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    Segway... :deal: :haha:
     
  18. jd70ssclone

    jd70ssclone 1/2 ton status

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    metrodps i think you mis understood me where i live i have to pass emissions thats all i was saying actually i would like to run mufflers with no cats but if there required i just wanted to know what to thats all. im not a liberal actually im only 16 and i wanted to find out what had to be done. i did watch the al gore movie in science if anyone needs to get a life its him hes just pissed cuz he lost for president thank you

    josh
     
  19. Metrodps

    Metrodps Strange but nice guy Premium Member GMOTM Winner Author

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    :haha: :haha: :haha:

    Buys josh a 12 pack of Dew! no offense taken bro!
     
  20. GruntHunter

    GruntHunter 1/2 ton status

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    Hey METROdps,

    When you switched pipes what did you do about your temp sensor. I was told that if you change from a single pipe to duals your exhaust will run cooler which the sensor will detect and think the engine is running cold and feed that back to your computer which in turn will screw up the engine performance, and probably milage. How did your conversion work out?
     

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