Do you have OEM CA emissions / smog equipment still in place?

[Bigdav160]

Can you post a pic of the SPID listing the CA emissions equipment? 3/4t emissions decals were different than 1/2t in 72. That you've listed is for a 1/2t application. 3/4t emission decals were located on the radiator support.

The only sticker remnants, on the core support, that I can see are for the coolant warning.

[Ed F]

Originally Posted by DeadheadNM

Thanks. I've been able to scrounge the parts but need to have the diverter valve rebuilt.

No 3/4t trucks had AIR - I believe these were emissions exempt.

I bought a ‘70 C-20 in January of 1970. It was a 307cu in and 3 speed manual trans. Not sure where it was built but I bought in Wheaton Illinois. It had the air pump on it. Was pretty common in those days to just take the belt off the pump. I accidentally hooked a radiator hose to the pump during a valve job... left a white smoke screen behind it like I was running moonshine. You don’t forget that experience.

[DeadheadNM]

Originally Posted by Bigdav160

The only sticker remnants, on the core support, that I can see are for the coolant warning.

Well I learned something new. Thanks for posting that's great info. Maybe one ton trucks were exempt? I'll post up an example pic of the non-CA 3/4t emission decal I mentioned.

Originally Posted by Ed F

I bought a ‘70 C-20 in January of 1970. It was a 307cu in and 3 speed manual trans. Not sure where it was built but I bought in Wheaton Illinois. It had the air pump on it. Was pretty common in those days to just take the belt off the pump. I accidentally hooked a radiator hose to the pump during a valve job... left a white smoke screen behind it like I was running moonshine. You don’t forget that experience.

I'd like to see more 3/4 t examples - good to know.

[toms68cst]

Bottom line... The Federal and California mandated smog controls changed a lot during the 1967-1972 model years.

I recall the first catalytic converters that came out in the mid to late 70's. How they stunk!

[leddzepp]

Originally Posted by Bigdav160

Here's the tag from my '72 California 3/4 ton 4x4 Suburban. I have no reason to suspect the fender well has been replaced. The engine has been replaced along with the exhaust. PO installed headers/aluminum intake. No AIR brackets left.

A suburban is not considered a commercial vehicle like a truck is here. It would make sense that it would have AIR vs. a truck.

[DeadheadNM]

Maybe that's it Scott. If anyone has a 3/4t 72 MY pickup with AIR or CA emissions on the SPID please post. Here's the best I can do at the moment as regards the non-AIR 3/4t emission decal - repro example placed in same location as original: I don't have a detail pic of the original decal now long gone. The replacement does reference both Federal and CA standards. If anyone has a detailed pic of a similar but original decal for a 72 MY 3/4t pickup please post.

[DeadheadNM]

....

[DeadheadNM]

Bumping this thread again to clarify. The spid pic above on the k20 suburban lists rpo YF5 (not YF6) which is a mandated emissions test performed on vehicles assembled in CA (this k20 is Fremont built). See rpo description below (thanks Jocko). The burb was not fitted with smog equipment at time of assembly.

[DeadheadNM]

Rpo YF6 denotes the AIR/smog equipment required on vehicles destined for sale in CA as shown on this blazer SPID.

[davischevy]

My SPID

[FirstOwner69]

I just read through this thread for the first time and am a bit confusesd on how broad based or year specific the disussion is focused. However, I can add that my '69 3/4 ton with A/C, 350 and TH400 has never had any emissions equipment other than a PCV valve. Not even a preheater, heat stove or whatever it's properly called. However, it did have a heat riser on the left side below the exhaust manifold. The truck was made in Fremont during Dec., 1968, and sold new to me in Yorba Linda, CA (Orange County, southern California). There is nothing on the SPID regarding emissions. Below is a picture of the original tune-up decal on the radiator support. It is identical to the reproduction and is upside down when read from the front of the truck. I have always wondered if it was oriented in this way by mistake or so it would be readable for a mechanic leaning over the fender with a timing light.

The emissions requirements were changing rapidly during these years, and I would would wager that almost every year had different requirements based on GVWR (3/4 ton vs. 1/2 ton).

[Rufas]

Originally Posted by FirstOwner69

I just read through this thread for the first time and am a bit confusesd on how broad based or year specific the disussion is focused. However, I can add that my '69 3/4 ton with A/C, 350 and TH400 has never had any emissions equipment other than a PCV valve. Not even a preheater, heat stove or whatever it's properly called. However, it did have a heat riser on the left side below the exhaust manifold. The truck was made in Fremont during Dec., 1968, and sold new to me in Yorba Linda, CA (Orange County, southern California). There is nothing on the SPID regarding emissions. Below is a picture of the original tune-up decal on the radiator support. It is identical to the reproduction and is upside down when read from the front of the truck. I have always wondered if it was oriented in this way by mistake or so it would be readable for a mechanic leaning over the fender with a timing light.

The emissions requirements were changing rapidly during these years, and I would would wager that almost every year had different requirements based on GVWR (3/4 ton vs. 1/2 ton).

During the time frame your truck was built emissions requirements for trucks in California lagged cars by several years. Pretty much all that was required for trucks was a PCV. 'IF' I remember correctly the PCV requirement started in 1965. Maybe a year or two earlier.

I grew up in southern Calif and as an early motorhead I remember dealing with all this emission crap. I even got ticketed a few times from the CHP for 'modifying' a smog equipped engine. Usually instead of a fine, just putting it back to stock got you off. When your 16 you could just about get away with anything then. That's doesn't happen now. And once the ticket was cleared then the mods went back on. My mother really hated going to traffic court with me. I must have drove my parents crazy growing up.

[DeadheadNM]

Originally Posted by davischevy

My SPID

3/4t tested for pending delivery to CA?

[Bigdav160]

Here's a SPID from a 3/4 ton Suburban in the Sub/Panel finds thread.

It looks to have YF5 and YF6



Maybe it was a Suburban thing

Interesting though, my Suburban doesn't have YF6 listed but has the LM emissions label like your Blazer

[Coley]

Here are a few quick of the system that one my (california) 1/2 ton when I got it a couple of years ago.
...I have removed all of this now and boxed it.

One thing that was interesting is that the truck was converted to headers so they added a group of bosses to both headers.
These welded on bosses had a 1/4"npt (1/8"npt?) fitting on them in order to attach the original 'a.i.r' manifold.

Hopefully this adds more information to the info pile.

All good
Coley

[DeadheadNM]

Good info here - thanks for posting.

[RedRoad]

Fremont began a.i.r. equipped engines in 66. For vehicles being shipped out of state they had to remove the a.i.r. system and had an RPO for Engine Conversion.

My brother has the family since new 1969 C20 with the a.i.r. smog equipment. It was a real pita to change valve cover gasket on the passenger side with the a/c compressor in place!

My 72 K20 Suburban had the original a.i.r. as well. The pump and bracket are still on the engine that came out of it and is in storage at my brothers house. Next time I go over Ill take a pic for you

The difference is the actual state regulations for the 1/2 ton vs. 3/4 ton truck. The lighter duty 1/2 ton had a tighter restriction while the 3/4 ton was allowed higher pollutant levels. When we still had to smog these things every other year my brothers truck never had an issue and the tech said it was the 7K GVW. Anything below had the passenger car restrictions.

[RedRoad]

Here is a pic of my smog decal

[DeadheadNM]

Thanks for posting. The SPID shows the K20 was tested per CA emissions (RPO YF5) but unless I'm missing it does not list RPO YF6, which is the actual engine smog equipment.

[Coley]

For the record and some follow up.....my truck (underhood stuff shown above) was a Fremont, California build....for California and it too has the YF5 California Reg on the SPID as well....but no YF6.
...not sure what that means, but more info for the operation.

All good
Coley

[Bigdav160]

Originally Posted by DeadheadNM

Thanks for posting. The SPID shows the K20 was tested per CA emissions (RPO YF5) but unless I'm missing it does not list RPO YF6, which is the actual engine smog equipment.

But he also has the LM emission sticker like my K20 Suburban. (Flint build)

[RedRoad]

Ive seen different wording for that RPO code, Ive seen both "testing" and "assy line equip". My K20 has A.I.R., and PCV installed. When smog was still being done on my trucks back in the 90s I asked the ref if I could remove the pump since so many other 3/4 ton trucks Ive seen did not have them. He said if during the inspection they saw any factory stickers showing it originally had smog equipment and it wasnt there it would fail visual then be sent to state inspection which usually was the death of most old vehicles.

[Bigdav160]

during the inspection they saw any factory stickers showing it originally had smog equipment and it wasnt there it would fail visual then be sent to state inspection

That's still true. The emission label is suppose to list emission control equipment fitted to the vehicle and could be the source of a failed visual.

Strangely, TSC and Evap is not listed on the LM sticker above.

[RedRoad]

I wonder if all fremont trucks just got every bit of emission equipment as it was developed. My K20 also has the evap and the TCS too.

[DeadheadNM]

Puzzling minutia but fun to sort out. Poor Fremont plant. Would like to see more SPIDs to parse the details out. Could it be that Fremont trucks used LM decals regardless of whether the vehicle was assembled with the YF6 equipment?

Here's a 1/2t BB block pickup AIR equipped with no YF5 or YF6 listed on SPID. Did all 72 1/2t pickups come with AIR equipment and therefore not listed on SPID?

http://67-72chevytrucks.com/vboard/s...postcount=1193

http://67-72chevytrucks.com/vboard/s...postcount=1192