Emission Control Questions 70 GS455 Stage1 and 72 Riviera

[ahaime]

Hi All,

I have a 70 GS455 Stage1 hardtop coupe that is not fitted with a vapor canister. I understand that canisters were only required on Califiornian cars - is that correct?

I also have a 72 Riv that was sold in California and has an air pump fitted. The heads are stamped "73". Is it correct to assume 73 heads were used because of the air pump?

Alan

[Brad Conley]

Hi All,

I have a 70 GS455 Stage1 hardtop coupe that is not fitted with a vapor canister. I understand that canisters were only required on Califiornian cars - is that correct?

I also have a 72 Riv that was sold in California and has an air pump fitted. The heads are stamped "73". Is it correct to assume 73 heads were used because of the air pump?

Alan

Hey Alan,

You are correct...in 1970 vapor canisters were only on vehicles destined for California. I know this all too well as in 1999 at the BCA National meet I "lost" points on my 1970 GSX because a "judge" said my car was wrong and needed a vapor canister (her husbands car had one, why didn't mine?? BECAUSE HER HUSBANDS CAR WAS SOLD IN CALIFORNIA ORIGINALLY!!!). Cost me a perfect score and a chance at best of show. I was pissed.

All 1972 model year Buick engines used an air pump and the 73 on the heads has nothing to do with that. Someone along the way switched the heads (or entire engine) along the way with 1973 model year parts. Correct 1972 model year heads would have a "72" where yours are marked "73".

HTH

[Duane Heckman]

I have a 70 GS455 Stage1 hardtop coupe that is not fitted with a vapor canister. I understand that canisters were only required on Califiornian cars - is that correct?

Yes, only 1970 Cars that were destined to be "sold" in California got the emissions/canisters and it was a totally different set up then found on the 71-newer cars.

I also have a 72 Riv that was sold in California and has an air pump fitted. The heads are stamped "73". Is it correct to assume 73 heads were used because of the air pump?

No, all 72 455 cars came with air pumps, as did 72 350 cars sold in California. If your heads have "73" cast into them they are probably from a 73 model year car.
Duane

[RatRiv]

I had a 72 Rivi, I still have the engine. Like mentioned before that is the year they started with the air pump and had air rails molded into the intake. My heads read "72" on them. You should look up the casting numbers on the heads and block. It will tell you if someone swaped just the heads or whole engine.