Did this K20 come factory with catalytic converter?

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Juke22

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Hello, I just bought a 1986 High Sierra 3/4 ton Camper Special 4x4.

I live in a state where emissions are required.

There's quite a lot of forum posts on the Internet that strictly state trucks with GVWR 8600 did NOT have catalytic converter in 1986.

However, the sticker under the hood is missing, and the emissions shop says my truck had cats in 1986, according to their book.

I've tried calling four different dealerships, and none could pull up my vin.. one of them told me this model truck had cats in 1986, based on his memory.

Someone shared this page, that shows the 5th character in my Vin is "K", meaning Light Duty Conventional 4x4.

Can anyone here give me a definitive answer? Thanks


...

The truck has a custom dual exhaust. I think the shop said I only need 1 cat.... Is that true, or would I need to get one for each pipe?

Options? Thanks
 

WebMonkey

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my 85 k20 has the C6P option which, as you said, put it over the threshold for 'no cats'.

i don't know the specifics of the camper special though a non C6P k20, of that era, would have cats i expect.

i'm no expert or even a novice at what a truck needs to pass inspection in states that require factory emissions equipment.
:)

good luck
'monkey
 

fast 99

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For 1980 through 1986, the same models as those for '79 used cats. However, a new C6P heavy duty option was offered for C/K 20/25 models which provided an 8,600 lb suspension package. These new, heavier 3/4 tons cleared the 8,500 lb limit,and so did not use converters during this time period, nor did C/K 30/35's.

For 1987 and beyond, all Chevy/GMC fuel injected engines used cats regardless of location or weight class. Only a few 30/35 series chassis cab models offered carbureted 292, 350and 454 engines, and those were the only models that did not use catalytic converters for 1987 on.

Note: The above applies only to U.S. vehicles. Canadian Chevy/ GMC trucks followed a much simpler story, I think. From what I have seen, no Canadian carbureted Chevy/ GMC C/K/R/V used cats, while all '87 and later fuel injected models did.
 

Keith Seymore

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and the emissions shop says my truck had cats in 1986, according to their book.
You have to determine your GVW.

Less than 8500 lb GVW - you need cats.

8600 lbs - no cats. And here is the documentation from GM (see page 39 of 188):

www.gm.com/content/dam/company/no_search/heritage-archive-docs/vehicle-information-kits/chevrolet-trucks/1986-Chevrolet-Truck.pdf[/URL]

In fact - that is the entire reason the RPO C6P=8600lb gvw was created: to put it above the 8500lb rating requiring emissions equipment.

Do you have the SPID label?

K
 

Keith Seymore

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fast 99

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GM Heritage shows no cats on all engines above 8600 GVW for 86 on page 39 both California and US. Couldn't link/paste the page.

With respect to light duty, until a vehicle reaches the 14-15k GVW all are considered "light duty". However, during that period emissions equipment in some cases was quite different between 8500 and 8600 GVW.
 

Juke22

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Thank you all for the fast response. I do not see any sticker in the engine bay, but I will post the ones from the door jam and glove box:

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my 85 k20 has the C6P option which, as you said, put it over the threshold for 'no cats'.

i don't know the specifics of the camper special though a non C6P k20, of that era, would have cats i expect.
If I'm reading my sticker right, I think I got the C6P? Thanks
For 1980 through 1986, the same models as those for '79 used cats. However, a new C6P heavy duty option was offered for C/K 20/25 models which provided an 8,600 lb suspension package. These new, heavier 3/4 tons cleared the 8,500 lb limit,and so did not use converters during this time period, nor did C/K 30/35's.
Do these stickers mean I have GVWR 8600 and C6P? Thank you
You have to determine your GVW.

Less than 8500 lb GVW - you need cats.

8600 lbs - no cats. And here is the documentation from GM (see page 39 of 188):

www.gm.com/content/dam/company/no_search/heritage-archive-docs/vehicle-information-kits/chevrolet-trucks/1986-Chevrolet-Truck.pdf[/URL]

In fact - that is the entire reason the RPO C6P=8600lb gvw was created: to put it above the 8500lb rating requiring emissions equipment.

Do you have the SPID label?

K
I found the SPID, and I've posted the decals I found, i think i got 8600GVWR? It also says "California Emissions"?? Thanks.
Doesn't matter.

All square pickups, even one ton doolies with 11000 and 12000 lb gvws , are considered "Light Duty" pickups.

K
I think this is looking good for me, thanks for info.
GM Heritage shows no cats on all engines above 8600 GVW for 86 on page 39 both California and US. Couldn't link/paste the page.

With respect to light duty, until a vehicle reaches the 14-15k GVW all are considered "light duty". However, during that period emissions equipment in some cases was quite different between 8500 and 8600 GVW.
Thanks for info, I think I might be in the clear with the 8600 GVWR? I think i found the page you mean, I see where it doesn't list "Oxidizing Reducing Converter" for HD emissions, and exempts C6P - I'll show that to the emissions shop. Thanks.

I also just noticed the sticker I posted says "California Emissions". Any idea what that means?

...

Great info, thanks all. This is my first truck, planning to fix it up, carry some dirtbikes and keep it forever.

I should add that the truck has a 305 put in it with custom exhaust. I don't think that should affect my original question, but I notice this engine was not put in HD trucks.

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Keith Seymore

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Yes - there was Federal Emissions, California emissions and High Altitude emissions (those were the choices). The content for each of those is explained in the packet.

You'll notice cats were not required for any of those over 8500 lb.

K
 

75gmck25

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You need to find a more experienced emissions station, and one that will actually look up and show you the data instead of using words like “always”. Most younger (and older) guys have no real knowledge what specific emissions was installed on a nearly 40 year old truck, so having them rely on memory is not good.

The catalytic converter exemption GVW threshold changed over time, and the manufacturers changed with it. The original non-cat GVW was for trucks over about 6100 lbs, which spawned the heavy half Chevy and F150 Ford, and the GVW level for the exemption increased over the years.

Your truck is clearly one with 8600 GVW, and there should be no dispute. My Camper Special even has the GVW as part of the Camper Special emblem on the side of the cab. If an ‘86 truck at 8600 GVW did not require a catalytic converter, then the emissions guy is clearly wrong.
 

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