1979 c30 crew cab dually & catalytic converters

[Dano69c10]

I just scored a 79 c30 crew cab dually, the PO said that it would not pass California emissions. I raised the hood and noticed that the driverside exh manifold was missing the AIR tubes. I also noticed that there were no catalytic converters for the dual exhaust. I figured I could score some AIR tubes easily, but did these trucks come with catalytic converters?
Thanx in advance
Dano

[EricS76]

Check your GVWR. Should be on a tag in the driver's doorjam. Since you have a C-30, it should be over 8500 lbs. In '79, 8500 lbs and over didn't have cats and probably not AIR. They really didn't have much except a PCV valve and an air cleaner that has the tube to the manifold and a flap that diverts the air in the air cleaner snout. That's nationwide, including CA.

[ElGracho]

My 83 C30 454 has no emissions stuff at all. It even has regular gas fuel fillers and the gas gauge doesn't say 'unleaded fuel only'. No cats. My truck was sold new in Texas, so I'm not sure what California would be.

[Dano69c10]

My c30 not only has AIR system, but two charcoal canisters, all sorts of vacuum hoses to at least three different types of switches and something on the passenger side exhaust. Do you think if I just left the PCV, EGR, A.I.R. system and pipe from exhaust to air cleaner that no one would question it? I'm sure the kid working the emission testing equipment would not know what belongs on the truck. When I have taken other cars for testing it seems like this is all they visuallly check.
Anyone from California out there? What's emissions are on your c30?
Dano

[CbHeEaVsYt]

my 82 was a california truck and it had the stock exhaust and it had two catalytic converters

[Dano69c10]

To be safe I'm gonna get the cats installed.
thanx Dano

[EricS76]

This from www.73-87.com


For 1978, all C10/15's with GVW's under 6,000 lbs have converters regardless of engine. All other '78 models (i.e. Big 10's/Heavy Halfs, K10's, C/K 20/25/30/35's)had GVW's over 6,000 lbs, and therefore did not use converters. EXCEPTION: For 1978, all California models with GVW's under 8,500 lbs had cats. Therefore, this California exception included ALL and ONLY 10/15/20/25 series vehicles, including Big 10's/Heavy Halfs.

For 1979, Federal laws, like California statutes in '78, raised the GVW threshold. So, all 1979 models, except for C/K 30/35 vehicles, had cats, nationwide.

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.

[KIILew]

Originally Posted by EricS76

This from www.73-87.com


For 1978, all C10/15's with GVW's under 6,000 lbs have converters regardless of engine. All other '78 models (i.e. Big 10's/Heavy Halfs, K10's, C/K 20/25/30/35's)had GVW's over 6,000 lbs, and therefore did not use converters. EXCEPTION: For 1978, all California models with GVW's under 8,500 lbs had cats. Therefore, this California exception included ALL and ONLY 10/15/20/25 series vehicles, including Big 10's/Heavy Halfs.

For 1979, Federal laws, like California statutes in '78, raised the GVW threshold. So, all 1979 models, except for C/K 30/35 vehicles, had cats, nationwide.

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.

Dano69c10:

Your '79 C30 dually pickup has a 10,000 lb GVW (or possibly a 9,000 lb GVW if it is a chassis cab model), and, consistent with the quote above (which I originally authored), was rated as a heavy duty emission class vehicle in California and in the other 49 states as well. Regardless of whether it has an LS9 350 or an LF8 454, your rig should have originally had the following emission controls (which for '79, are shared by the 49 state and California heavy duty emissioned models):

PCV-Positive Crankcase Ventilation
ECS-Evaporation Control System (i.e. your charcoal canisters)
EFE-Early Fuel Evaporation (i.e. that valve in the R.H. exhaust manifold)
TRC-Throttle Return Control
CHA-Carburator Heated Air (i.e. the heat stove to your air cleaner)
AIR-Air Injection Reactor (air pump)
TVSS-Trapped Vacuum Spark System (i.e. assorted vac. tubes/switches)

This listing is also applicable to '79 K30's with the LF4 400 engine.

I noticed that you implied that you have EGR on your engine. That surprised me, because EGR was used on California heavy duty emissioned 454's prior to the '79 model year, but was not cataloged for any heavy duty emissioned V8's used in '79 to early-'85 model year pickups. It reappeared on the heavy duty emissioned 350 and 454 engines (both 49 state and California) just after the start of the '85 model year.

Translation to the above: I would not expect to find EGR originally equipped on your '79 C30. The above listing originally was compiled using original GM data books, but emission schematics for your engine as found in Chiltons, etc. also support the exclusion of EGR from your '79 California heavy duty emissioned 350/400/454. Of course, GM can do whatever they want, regardless of what they print, and I have personally seen some variation particularly with respect to air pump and EFE application. But I would question the necessity- -and originality- -of EGR on your rig.

Regardless, I am confident your vehicle did NOT come equipped originally with a catalytic converter.

Ken Lewis

Later edit: p.s. sorry about the 350 and 400 references; I just noticed in my second reading that your signature confirms that your rig has a 454. The info applies to all three engines, however.

[Dano69c10]

Oh man thanx for that info, I got prices for cats today and the wife told me to get rid of the truck. the guy at the muffler shop told me that I needed them, (maybe he needed me to have them.) You know I thought I had EGR, but I made a mistake.
Again thanx for the info, the c30 (and me) stays.
Dano

[Tx Firefighter]

Originally Posted by Dano69c10

Oh man thanx for that info, I got prices for cats today and the wife told me to get rid of the truck. the guy at the muffler shop told me that I needed them, (maybe he needed me to have them.) You know I thought I had EGR, but I made a mistake.
Again thanx for the info, the c30 (and me) stays.
Dano

You can buy a good replacement cat converter from Summit real cheap. Last one I bought was under a 100 bucks.

[KIILew]

Originally Posted by Dano69c10

Oh man thanx for that info, I got prices for cats today and the wife told me to get rid of the truck. the guy at the muffler shop told me that I needed them, (maybe he needed me to have them.) You know I thought I had EGR, but I made a mistake.
Again thanx for the info, the c30 (and me) stays.
Dano

If my info helped, glad to be of service. It is always a priviledge to help preserve a man and his truck...

Ken Lewis

[mike505]

I got in arguements with 3 exhaust shops in Georgia over this. My '84 C-30 Crew Cab is rated at 10,000 GVWR and they told me it had to have cats installed. I finally found a shop that did the exhaust without them but it wasn't easy. I looked it up at the time and I believe over 8500 GVRW didn't require them.

Where I lived we didn't even have insprections. When we moved back to Florida a few months ago the local tag office tried to get me to register it at 6999 GVWR and I said no way. Florida has inspections in some counties and I don't need the grief if we wind up in one. What I'm saying here is check to see if somebody changed the weight rating at some point. If so hopefully you can change it again.

Mike

[Dooley]

I can't speak for Ca. emissions vehicles but, I owned/bought new a K30 in 77,79, and 80. All 3 had the 400sb and Turbo 400 and dual exhaust. These trucks were rated for LEAD Premium fuel. None had an egr or cat. The 79 & 80 had the air pump with only a single hose/pipe on one side for recirculation system.