Emissions Parts on a 350

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Chevrolado

Full Access Member
Joined
Dec 13, 2012
Posts
395
Reaction score
117
Location
McKinney, TX
First Name
Dave
Truck Year
2006
Truck Model
Silverado
Engine Size
V8
Hey all,
I think I have an opposite thread of the normal trend here.. hah. I searched around for emissions and SMOG information and whatnot, but I'm finding a lot of "removal" information and "what good are these parts" types of threads but not so much details on what parts they are for the middle years.

So here's the issue I have.. I have a 77 Arizona-built K10 with a 350, headers, all SMOG Emissions stuff removed, etc.. It's a good motor.
But I need to get it converted over to California SMOG legal emissions setup so I can get it re-registered here and legal to drive on our roads.

So I guess my overall question would be; what is the required SMOG Emissions gear for a normal 1977 350 (what items do most of y'all remove?) and what do I need to track down and put on to this thing to pass the tests? :shrug:

Thanks for any help or links towards help I can get here. :cheers:
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
10,229
Reaction score
14,584
Location
Right where I am
First Name
Bagoomba
Truck Year
1981, 1965
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s; 65-C20 with 4:57 gears and Borg Warner Overdrive
Engine Size
Carb'ed Vortec 350; 1972 L48 350
Contact a Referee. I think the emissions is pretty minimal in that year. Probably similar to what I have on my 81 C20, which is next to nothing. Let me dig up a picture.
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
10,229
Reaction score
14,584
Location
Right where I am
First Name
Bagoomba
Truck Year
1981, 1965
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s; 65-C20 with 4:57 gears and Borg Warner Overdrive
Engine Size
Carb'ed Vortec 350; 1972 L48 350
The pics aren't that great, but the passenger side you can see the smog pump under the alternator, and the tubes that go into the exhaust manifolds, and some canister thing that attaches to the exhaust butteryfly.

The right side is just the tubes that go into the exhaust manifolds.

Top view shows the hose going over to the smog pump tee.

And the vacuum hose routing. Keep in mind this is for an '81 C20 built in January of 1981, and there were many different scenarios for this year. But it is about as basic as you can get and should get you to pass emissions as long as you can find the parts to add back to the truck.
 

Attachments

  • 30 Engine Right.jpg
    30 Engine Right.jpg
    94.7 KB · Views: 497
  • 31 Engine Left.jpg
    31 Engine Left.jpg
    96.1 KB · Views: 504
  • 29 Engine Top.jpg
    29 Engine Top.jpg
    94.9 KB · Views: 470
  • 2012-08-05_17-10-17_567.jpg
    2012-08-05_17-10-17_567.jpg
    99 KB · Views: 543

Chevrolado

Full Access Member
Joined
Dec 13, 2012
Posts
395
Reaction score
117
Location
McKinney, TX
First Name
Dave
Truck Year
2006
Truck Model
Silverado
Engine Size
V8
Awesome! You rock. Thanks for the info. That definitely gives some direction to head. I really appreciate the quick reply and the pictures to assist. :)

I'm going to need to change some of these things around to get all that situated.. :(

You must be registered for see images attach


So I guess I should start looking for exhaust manifolds, SMOG pump and plumbing.
Side question.. do you think I HAVE to have the whole intake canister? Or do you think I can get away with the open air filter setup I have?
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
10,229
Reaction score
14,584
Location
Right where I am
First Name
Bagoomba
Truck Year
1981, 1965
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s; 65-C20 with 4:57 gears and Borg Warner Overdrive
Engine Size
Carb'ed Vortec 350; 1972 L48 350
You're welcome. Glad I could help. At least you already have the water neck that has one of the smog components on it. I don't know exactly how it works, but I think the coolant warms up and then the sensor or whatever is on the neck opens or closes and then something goes on with other components of the system. There are others on here that know what all of those parts and pieces are called and do.

From what I understand you can have bungs welded into the headers for the emissions tubes, but stock manifolds would probably be easier. The open filter should be fine as long as all the other stuff is hooked up.
 

Chevrolado

Full Access Member
Joined
Dec 13, 2012
Posts
395
Reaction score
117
Location
McKinney, TX
First Name
Dave
Truck Year
2006
Truck Model
Silverado
Engine Size
V8
You're welcome. Glad I could help. At least you already have the water neck that has one of the smog components on it. I don't know exactly how it works, but I think the coolant warms up and then the sensor or whatever is on the neck opens or closes and then something goes on with other components of the system. There are others on here that know what all of those parts and pieces are called and do.

From what I understand you can have bungs welded into the headers for the emissions tubes, but stock manifolds would probably be easier. The open filter should be fine as long as all the other stuff is hooked up.

Oh yeah.. I noticed that funky water neck at one point as well - didnt know what it was for though. Glad to hear that is one of my needed parts. :)
Thanks for the help. Hopefully more can chime in and help with any additional information as well!
Yeah.. I'm thinking manifolds are probably fairly easy to come by. So that is probably the route I'll go.
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
10,229
Reaction score
14,584
Location
Right where I am
First Name
Bagoomba
Truck Year
1981, 1965
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s; 65-C20 with 4:57 gears and Borg Warner Overdrive
Engine Size
Carb'ed Vortec 350; 1972 L48 350
I wish I had some emissions parts laying around, I would help you out. The only emissions parts I can ever recall seeing loose in a milk crate was the ones from my dad's '79 GMC, and my brother threw those away in '97 when he cleaned out our dad's place. That crate would have had everything you needed.
 

Chevrolado

Full Access Member
Joined
Dec 13, 2012
Posts
395
Reaction score
117
Location
McKinney, TX
First Name
Dave
Truck Year
2006
Truck Model
Silverado
Engine Size
V8
I wish I had some emissions parts laying around, I would help you out. The only emissions parts I can ever recall seeing loose in a milk crate was the ones from my dad's '79 GMC, and my brother threw those away in '97 when he cleaned out our dad's place. That crate would have had everything you needed.

hah. Thanks! That would have been really nice. No worries though. I'd be willing to assume others have those same type of milk crates of estranged emissions parts as well. Just need to track down someone willing to part with theirs.

The other option I might have is to steal from other vehicles around the shop.. My father in law has a early 80's 383 suburban that probably has some parts.. Or I think he has an early 70's El Camino as well that I could probably talk him into "upgrading" his motor... and I'll clear out his old parts for him. hah! :angels2:
 

TheGreenBarron

Full Access Member
Joined
Jul 22, 2015
Posts
61
Reaction score
0
Location
Heber, CA
First Name
Sergio
Truck Year
1978
Truck Model
K10
Engine Size
350
smog parts

Awesome! You rock. Thanks for the info. That definitely gives some direction to head. I really appreciate the quick reply and the pictures to assist. :)

I'm going to need to change some of these things around to get all that situated.. :(

You must be registered for see images attach


So I guess I should start looking for exhaust manifolds, SMOG pump and plumbing.
Side question.. do you think I HAVE to have the whole intake canister? Or do you think I can get away with the open air filter setup I have?

You are going to need a factory air cleaner "canister" there is also a metal pipe that connects to the underside of the air cleaner that leads to the passenger exhaust manifold. Without those items it will not pass a visual inspection.
I have a 78 K10 with all the facotry emission equiptment still under the hood.
 

Chevrolado

Full Access Member
Joined
Dec 13, 2012
Posts
395
Reaction score
117
Location
McKinney, TX
First Name
Dave
Truck Year
2006
Truck Model
Silverado
Engine Size
V8
You are going to need a factory air cleaner "canister" there is also a metal pipe that connects to the underside of the air cleaner that leads to the passenger exhaust manifold. Without those items it will not pass a visual inspection.
I have a 78 K10 with all the facotry emission equiptment still under the hood.

Drats. I was worried about that part. I saw on a couple 350's I looked into that there is that pipe running from the intake down to the manifold. Was hopeful that it wouldnt be necessary for mine. hah. :(

Do you have any pics of your motor setup we can get in this thread for reference to the way a standard 78 K10 would be setup?

Thanks so much!
 

TheGreenBarron

Full Access Member
Joined
Jul 22, 2015
Posts
61
Reaction score
0
Location
Heber, CA
First Name
Sergio
Truck Year
1978
Truck Model
K10
Engine Size
350
Smog parts

Drats. I was worried about that part. I saw on a couple 350's I looked into that there is that pipe running from the intake down to the manifold. Was hopeful that it wouldnt be necessary for mine. hah. :(

Do you have any pics of your motor setup we can get in this thread for reference to the way a standard 78 K10 would be setup?

Thanks so much!
That part is pretty easy to replace i know there are universal flexible pipes that can be bought at many parts stores. You will likley need an intake with provisions for an egr valve if your intake doesnt already have it. Another thing i just thought of are the canisters for the fuel tank or tanks depending on your setup. They are supposed to catch the fumes from the tanks and sent them to the carb.
My truck is in my dads care at the monent but ill be paying him a visit soon ill take all the pictures i can.
 

Chevrolado

Full Access Member
Joined
Dec 13, 2012
Posts
395
Reaction score
117
Location
McKinney, TX
First Name
Dave
Truck Year
2006
Truck Model
Silverado
Engine Size
V8
That part is pretty easy to replace i know there are universal flexible pipes that can be bought at many parts stores. You will likley need an intake with provisions for an egr valve if your intake doesnt already have it. Another thing i just thought of are the canisters for the fuel tank or tanks depending on your setup. They are supposed to catch the fumes from the tanks and sent them to the carb.
My truck is in my dads care at the monent but ill be paying him a visit soon ill take all the pictures i can.

Ah okay, that makes sense.
This rig has dual tanks. Okay, I'll check into that as well then. Thanks!
If you can grab some pics for me next time you see it, that would be greatly appreciated! Thanks so much.
 

skysurfer

Full Access Member
Joined
Oct 23, 2010
Posts
2,648
Reaction score
2,023
Location
west coast
First Name
John
Truck Year
1989 Suburban
Truck Model
V2500
Engine Size
5.7/TH400/NP241C
You really need to check with a referee before you do anything. The equipment requirements vary from year to year, the max gvwr, and whether or not it was originally a California or 49-state vehicle. I would expect the basic pcv, fuel evap canister, thermostatic air cleaner, and maybe an egr... but the air injection is a crap shoot and you don't want to deal with it if you don't have to.

I smog tested a couple-hundred thousand vehicles from that era and we needed a big **** computer to tell us what to look for. Don't rely on any forum for exact information with regards to your specific vehicle, it's too time consuming and expensive to guess wrong.
 

Chevrolado

Full Access Member
Joined
Dec 13, 2012
Posts
395
Reaction score
117
Location
McKinney, TX
First Name
Dave
Truck Year
2006
Truck Model
Silverado
Engine Size
V8
You really need to check with a referee before you do anything. The equipment requirements vary from year to year, the max gvwr, and whether or not it was originally a California or 49-state vehicle. I would expect the basic pcv, fuel evap canister, thermostatic air cleaner, and maybe an egr... but the air injection is a crap shoot and you don't want to deal with it if you don't have to.

I smog tested a couple-hundred thousand vehicles from that era and we needed a big **** computer to tell us what to look for. Don't rely on any forum for exact information with regards to your specific vehicle, it's too time consuming and expensive to guess wrong.

Many thanks for the quality information. How do I go about getting a hold of a referee to setup some sort of check-over?
I definitely agree this is probably the right way to go here. Have them tell me exactly what it needs.. then I can go do that. Rather than guessing and throwing parts and money at it.
Thanks!
 

Forum statistics

Threads
42,195
Posts
911,116
Members
33,687
Latest member
Dale Downes
Top