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Do i need catalylic conveters

Discussion in 'Chevy Truck Talk & GM News' started by Bmx4397b, Aug 16, 2012.

  1. Bmx4397b

    Bmx4397b New Member

    i have a 1986 gmc pickup it came with a 305 i recently swaped motors to a 1974 350 cmj i was wondering if i need cats thanks
    Bruce
  2. moogvo

    moogvo Epic Member 5+ Years 1000 Posts

    If the vehicle came with them, then it needs to have them. That's the short answer.
  3. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    This is a tricky question since you've got an earlier engine in a later model body, 74's didnt require or have convertors when they were manufactured, 86's did have them, the real answer is gonna be what your state Clean air board says is right. Some states go by the engine year for requirements and some states go by the body year, what does NJ go by?
  4. Conlan Rose

    Conlan Rose Active Member 2 Years 1000 Posts

    In CT to pass inspection you just have to see them doesn't mean anything has to be in them. Not sure about NJ tho.
  5. Bmx4397b

    Bmx4397b New Member

    Lol i was thinking about doing that
  6. Bmx4397b

    Bmx4397b New Member

    I have know idea
  7. Conlan Rose

    Conlan Rose Active Member 2 Years 1000 Posts

    What you really need to find out is what you have to do for emissions some states if you have an engine that isn't factory to the car you can register it as a custom car so it doesn't have to pass normal emissions it just need to pass inspection.
  8. Gryphon

    Gryphon Rockstar 100 Posts

    Cats are a tricky legal issue because it's more than state law, there's federal laws involved too. The current generation of cats do not block flow like the early ones did by any means. I'd toss on a pair of racing cats from Summit or Jegs, or at least their universal cats. THey claim no performance loss and it keeps you legal. In either case, they are a good thing for burning the unburnt hydrocarbons left int he exhaust. Thinking thermal-dynamics, hot air scavenges faster than cooler air and cats really heat up the exhaust air, not to mention the benefit for exhaust pollution. I've been living in a very rural desert town north of LA and we get LA smog. It's not as bad as it used to be, but it's still bad. Cats are a good thing.

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