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MANATORY CAT. CONVERTER 1st YEAR?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BLUESMAN, Oct 19, 2001.

  1. BLUESMAN

    BLUESMAN 1/2 ton status

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    I researched this subject before I posting so please do not refer me to search again.The research stated that cats. started being manatory in 77.But my 78 (that I bought new) did not have a converter.So what year did they(cats.) become manatory?BTW my 79 did not have cats either(bought it used though in 85).Please help me out as I still haven't bought a Blazer and want to look for a good year.thanks!
     
  2. TXBIGFISH

    TXBIGFISH 1/2 ton status

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    For a while it depended on GVW, where are you located and fill out your profile.

    <*)))><

    81" GMC Jimmy.............stock for now!
    I see a 6 inch lift in the near future!
     
  3. muddin4fun

    muddin4fun 3/4 ton status

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    It depends on the state and county you live in. Where I live, you can pass inspection without cats up to '84.

    Peace and stuff [​IMG],

    Muddin

    <a target="_blank" href=http://www.geocities.com/muddin4fun79blazer>www.geocities.com/muddin4fun79blazer</a>
     
  4. HarryH3

    HarryH3 1 ton status Author

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    When cats first appeared on cars, the EPA rule was that any vehicle with a GVWR of 6,000 lbs or more did not need them. Ford added another leaf to the rear spring pack of the F-100 and called it an F-150. GM came out with the "Heavy Half" 1/2-ton trucks. They had GVWR's of something around 6,050 lbs so they weren't required by law to have the cats. K5's were over the limit as well. In later years the GVWR limit went up to 8,600 lbs. It may be even higher today, but since that's well beyond the GVWR most of us use ('cept Wes and his K30's!) it's irrelevant.

    Early attempts at emissions totally sucked. 135 HP V8 Camaros and the like were the result. They ran like crap, got lousy mileage and just weren't any fun to drive. Today you can buy 400+ HP 350's right off the showroom floor in new Corvettes that run amazingly clean. Just proof that you can have a cat in place and still make plenty of power. [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <a target="_blank" href=http://www.angelfire.com/super/ThunderTruck>www.angelfire.com/super/ThunderTruck</a>
    It's a great day to be alive...
     
  5. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Is the core support tune up sticker still there? If it was a Cat truck it would say in bold letters right across the top CATALIST. If it's not there then hopefully the emmisions NAZI's will have the correct info in their computer showing that vehicle did not come with a cat.

    Women dig dents and flat paint!
    <a target="_blank" href=http://communities.msn.com/OffroadK5s>communities.msn.com/OffroadK5s</a>
    75 Jimmy, Dollar
    Grim-Reaper
     
  6. BLUESMAN

    BLUESMAN 1/2 ton status

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    Thanks for the info.I'm trying to narrow my search for a Blazer and want to run w/out cats..Does anyone know if cats came on an 80?I realize this is an open ended Q but like i said I'm still looking.I found an 80 with 350/th350 and (rare?.....Std.)205 x-fer case for $850.I'm still waiting for a call back!Thanks1
     
  7. HarryH3

    HarryH3 1 ton status Author

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    Why the big desire to run without cats? The cat really doesn't make that much of a difference. Find a truck that you like and enjoy it. [​IMG] One of the go-fast magazines tested a high flow cat against a straight pipe a while back and the dyno showed something like a whopping 3 HP decrease with the cat in place. [​IMG] Doesn't seem to me like much of a reason to avoid a specific vehicle. [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <a target="_blank" href=http://www.angelfire.com/super/ThunderTruck>www.angelfire.com/super/ThunderTruck</a>
    It's a great day to be alive...
     
  8. BLUESMAN

    BLUESMAN 1/2 ton status

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    The only reason I have is the additional expense of a atermarket converter($100).I'm trying to build this project cheap but functional....no pretty frilly things for me!The only thing chromed will be the shifters.Just trying to get the project done on paper before I start making/buying mistakes.....I've learned the hard way too many times!Thanks.
     
  9. MaxCrack

    MaxCrack 1/2 ton status

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    In California, I believe they started putting cats on some 75's. And if you don't have one (like I used to have none) you have to prove that it came that way from the factory or put one on (like I had to do). Or find a tester that doesn't care, but that's a little harder to do.

    Some days I just pray for spontaneous combustion
    <a target="_blank" href=http://photos.yahoo.com/dana60manual>http://photos.yahoo.com/dana60manual</a>
     
  10. bigjbear

    bigjbear 1 ton status Staff Member Moderator

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    My 78 did not have one and did not come with a filler neck reducer. If it had a cat it will either have the reducer or you will be able to see where it was cut/knocked out and the fuel gauge will say "Unleaded Fuel Only". My 78 was listed as HD emmissions. I think that means it had an extra leaf in the packs. It had 3 in front &amp; 8 in back, those may have been added by a P.O. though.

    Jim '80 GMC & '73 Blazer
    Body by Tellico
    <a target="_blank" href=http://www.tellicok5.rockcrawler.com>www.tellicok5.rockcrawler.com</a>
     
  11. BLUESMAN

    BLUESMAN 1/2 ton status

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    Yes I remember now....it took leaded fuel and was the HD edition(Hd spring packs).That was a long time ago...sold it in 87,I bought it new in 78.
     
  12. 84_Chevy_K10

    84_Chevy_K10 Banned

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    By 1980, all trucks should have had cats.

    The big desire to go without a cat is that it sounds like crap if you have one on there. Actually, not only does it sound like crap, it's about as quiet as a car, even without mufflers too.

    Well, the Vortec cats are cool. I don't know what's inside them, but emissions legal straights on a Vortec 350 sound MEAN with 2 1/2" pipe.

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     

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