1970 Emissions label questions

[Tom L.]

I have a 1970 LS-5 with an "AS" on the emissions label. I have three questions:

1)What do these letters mean?
2)Where can I buy a replacement? The replacement part vendors only carry the more popular labels; and
3)The TIM lists an "AS" label on a California emissions car. What's left of my tank sticker does not list the Ca. emissions code. Also, my research indicates that the car spent it's first 37 years in Indiana. What else on the car would indicate Ca. emission?

Thanks.

[Dick W.]

Re: 1970 Emissions label questions

For California emissions cars, NA-9 option, there should be an evaporative emissions cannister on the left side inner fender area right in front of the cowl.

[Dave P.]

Re: 1970 Emissions label questions

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[Jack H.]

If I remember correctly...

the Cal emissions option, NA9, started life as an option available to dealers in all 50 States. Then, some in California 'bitched' that their customers were crossing the border to buy from other non-Cal dealers and the option was 'controlled'...

That would suggest that it's possible for the car to have been initially delivered in Indiana and still have been NA9 equipped. But, some of this may be old wife's tale.

It's strange that California represented approximately 10-15% of Chevy's buying audience and we ALMOST NEVER see NA9 equipped Corvettes at judging meets!

[Tom L.]

Re: 1970 Emissions label questions

There's no canister, nor are there any lines or hardware to suggest that there ever was. Could the "AS" designation on the emissions decal be unrelated to the NA9 option?

[Joe L.]

Re: 1970 Emissions label questions

Tom------

It's possible that the "AS" emissions coding related to something other than NA-9 emissions. This is a quite rare code; I've never seen one. Is yours in good enough shape that you could either scan it or photograph it in such a way that the text would be readable? I might be able to discern something about it from what's on it. In any event, I would like to see it.

[Tom L.]

Re: 1970 Emissions label questions

Here it is.

[Joe L.]

Re: 1970 Emissions label questions

Tom-----

Thanks. It's too bad that a lot of the left side of the label has been worn away. It's hard to make out anything that's important. However, I do note one interesting thing that I can see on the right side of the label. Note that it refers to adjusting something until a drop of 40 RPM is achieved. An adjustment or step involving a 40 RPM drop is not mentioned on any other of the 1970 emissions labels that I'm aware of. So, that instruction appears to be unique to this "AS" label (unless there are other 1970 labels/emission codes, also unknown to me, which have a similar instruction).

Keep in mind that the 1970-72 period, and even for quite a few years after that, was a period of much "flux" in the world of emissions. There were conflicting regs beginning in 1970 (i.e. California and federal) and I don't think that the manufacturers had really figured out what was supposed to be happening. Also, note that the part number on this label is very close in numerical sequence to several others that are more well known. That implies that it was released as part of a "series" of emission codes rather than a later-issued, stand-alone "quick fix" type of thing.

[Tom R.]

Re: AS is the broadcast code...

but there would be other remnants of NA9 if indeed it was installed. For example, the steel vapor line would run back to the fuel tank and even if removed, its connection to the tank (or in those years the liquid/vapor separator may remain. I believe its on the cabin side of the fuel tank up in there. I believe it would also have been equipped with the sealed gas cap...but the 70 guys can detail the specifics equipment wise.

If indeed your AS is the NA9 option, than the calibrated carb would carry the 7040505 (or 504 if AT) number and you can triangulate that with the engine suffix code.