Anyone have an 1984 5.7 Code M emissions decal picture?

[rick1956]

I just wondered if anyone out there has an 84 with the Code M 5.7 in it that they wouldn't mind taking a picture of? My GMC 2500 has no decal, and I'm just curious. I'm not looking to recreate... just want to see everything that is supposed to be written on it.

It's the decal on the radiator support.

Thanks!

[Keith Seymore]

While not the decal itself the attached information shows what equipment is included, and might help you make sure everything is present and accounted for. Pages 114-117.

https://www.gm.com/content/dam/compa...olet-Truck.pdf

The detailed powertrain information is not contained in every generic info packet (and was not in the 1984 information), so I've attached the 1983 info. I would expect it to be the same up to 1986.

K

[Keith Seymore]

Originally Posted by rick1956

Code M 5.7

What's the "Code M"? Is that the VIN code?

Are you able to relate that back to the engine RPO (like LT9 or LS9)?

K

[rick1956]

The code M guys had less emissions equipment (less car, more truck?) or something similar. I have all the information shown on those decals, I was just interested in the layout and look of the code M decal. The code L trucks are the LS9 designation while the code M trucks were the LT9 designation.

Kind of a "hmm, I wonder how different the decals look from the code L trucks?"

For example, my code M truck doesn't use the fuel canister--it has the fuel tanks venting to the outside. The manual shows completely different engine wiring on the code L trucks--lots of ESC goodies on that model. There are lots of differences between the two trucks--I'm just wondering what the decals look like and what they show.

[Keith Seymore]

Could be.

The level of emissions equipment required was determined by GVW.

K

[rick1956]

Here's another example... notice an important item missing from the "M" trucks? I imagine someone that has to have their "M" code truck sniff tested would sure be glad to have that label to keep them outta EPA jail! haha

[v30crewcab]

I think my buddys burb is m code. I'll have to see if it still has its emissions label.
My 86 k30 has a m code emissions label on the air cleaner, would that help?

[Keith Seymore]

Originally Posted by v30crewcab

I think my buddys burb is m code. I'll have to see if it still has its emissions label.
My 86 k30 has a m code emissions label on the air cleaner, would that help?

No.

LD vehicles (ie 10 and 20 series) certify the vehicle, which is why the label is on the radiator support.

HD emissions certify the power train, which is why the label is on the air cleaner.

K

[rick1956]

Hell, I'll take any pics you can toss at me that are in the ballpark. It's all new if I've never seen it!

[v30crewcab]

my buddys burb didn't' have a sticker. I haven't had a chance to take a pic of my aircleaner one yet.

[Keith Seymore]

Found one for the 305 cu in engine. I gotta believe it's very similar to a LD 350.

K

[Keith Seymore]

Gonna need to know Federal Emissions vs California Emissions, too.

I'm not optimistic. The offerings in the aftermarket are spotty at best.

K

[THI]

I had a 1986 K20 (8600 GVW) with the 350 engine and the VIN code for the engine was "M". Since it was greater than 8500 GVW it was considered Heavy Duty Emissions and did not have a catalectic converter - it did have a factory dual exhaust and the Emission Sticker was on the air cleaner.

The charts I have show the Light Duty Emission 350 as VIN code "L" and the Heavy Duty Emission 350 as VIN Code "M" for 1984 as well as 1986 and was consistent from 1981 through 1986. According to the chart that Keith Seymour posted you would have the LT9 (RPO) engine and the chart lists the emission equipment for that engine - looks like no specific CA emissions on Heavy Duty trucks that year.

[rick1956]

That may explain why there's no shadow on the radiator support where a sticker used to reside. You'd think there would be one regardless--for basic timing spec, etc. I'll just hold out for an air cleaner pic then. Thanks man

See? This is why I love this site!

[Pontiac1976]

Do know if the rad support has been changed. That would be another reason for no sticker. The after markets rad supports pretty thin at the top motor side have some sharp unfinished bends the center support of the rad under the latch very thin best give away. Factories are long gone. Good luck in your search.

[v30crewcab]

heres my sticker