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1971 Riviera GS Engine Code Question


Centurion

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I was contacted during the weekend by a friend who has just purchased a nice 1971 Riviera GS. He is a BCA member and has just joined the ROA.

He would like to confirm that the car has the modified High Performance 455 of the Riviera GS.

I am unable to locate my 1971 Buick shop manual. Can someone tell me where the engine code can be located and what the code should be for the High Performance 455?

I did locate my 1971 Buick Facts Book, which indicates that the Riviera GS should also be equipped with the 3.42 posi-traction rear axle. Is this consistent with the '71 Riviera GS's that you've seen?

Thanks in advance for your help.

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According to Darwin Falk's article on '71 - '72 GS's in a past Riview, a W was used in identifying the Stage 1 engine in the GS, BUT Buick did not start that until the 1972 models. Don't know if there is anything in the VIN to identify a '71 GS.

Ed

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Ed, you are correct that the engine is not indicated in the 1971 VIN, so what I'm looking for is information regarding the engine code on the block itself.

And it is also my understanding that the High Performance 455 of the Riviera is not a Stage 1 engine, but does have Stage 1 heads. The actual Stage 1 engine had a hotter cam, different fuel pump, different carburetor, etc.

Edited by Centurion (see edit history)
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Brian,

The original 71 riv GS engine will have a TA code stamped between the 3rd and 4th spark plug front to back on the left (driver) side of engine. Along with the 2 letter designation will be a 3 digit production code.

There is also a VIN number stamped on front of the engine block which I believe was also on the left bank. It may be hidden by the PS pump or other brackets.

The transmission was also stamped with a matching VIN in 1971 so he can verify if it has the original tranny as well.

The 71 GS Riv was in fact equipped with the 3.42 limited slip.

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The engine code for the 71 GS Riv should be TA. The "W" did not start until 72. The 71 TA engine is a true Stage 1 engine as it does have a different cam, bigger intake & exhaust valves. GM engineer Dennis Manner who developed the 455 engine, sent me all the pictures and documentation.

Bob Bonto #277 ROA

Technical Advisor 71-73;)

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Thank you, Bob. I've been told that the cam, while different from that in the standard "TR" 455, is also different from that utilized in the Skylark-based GS Stage 1 cars. In fact, it appears that the Skylark-based Stage 1 cars have a "TS" engine code.

I've read that Buick determined that the wilder cam of the Skylark-based Stage 1 cars was not smooth enough for use in the Riviera or other, luxury-oriented full-size cars. (The Riviera GS engine was also an option on the Centurion series cars.)

Am I correct about this? I don't claim any expertise; I'm just trying to learn the facts. If the Riviera GS engine is considered a Stage 1 engine, then it appears that Buick was building two, different Stage 1 engines during this time?

Am I correct in thinking that the '73 Riviera GS actually wore a Stage 1 grille badge? Does this mean that Buick was no longer referring to the engine as the modified "High Performance" 455, simply calling it the Stage 1 instead?

Edited by Centurion (see edit history)
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Neil,

Open the ROA's website www.rivowners.org and go to the Member's Only section. In the "Articles from the Riview" link there's another link called "ID a Grand Sport." On page three of that article Darwin Falk goes into great detail on how the Stage 1 and Gran Sport models were identified for '73 as well as what other modifications were part of the Gran Sport package for that year.

Ed

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Neil,

You are correct. As the article states (Here I've pasted and copied from the article) During these years (73 and 74) the GS option was a ride and handling package only.

In '73 the GS option was identified with Gold emblems, and the Stage 1 engine option was identified with a grill badge (and the W in the VIN); you could get both and the car would have both ID's.

What I can't tell from the article or the production figures at the end of the article is this: Could you order the Stage 1 engine and not get the GS package? Were theytwo separate options? You could get the GS option by itself, but to get The Stage 1 option, did you have to order the GS option as well? Perhaps someone will make this more clear.

Ed

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What I can't tell from the article or the production figures at the end of the article is this: Could you order the Stage 1 engine and not get the GS package? Were theytwo separate options? You could get the GS option by itself, but to get The Stage 1 option, did you have to order the GS option as well? Perhaps someone will make this more clear.

Ed

It seems we have really opened a can of worms on this subject. So please allow me to try and answer everyone's questions.

Centurion,

Yes Buick used two different cams and were building two Stage 1 engines. According to the letter and documentation that Dennis Manner sent me. The Riviera GS/Stage 1 engine and the Skylark GS Stage 1 both used 1/8" oversize intake and exhaust valves. While the Riviera GS/Stage 1 engine camshaft did have more lift, the Skylark GS/Stage 1 camshaft had significantly more duration for more top end power.

I also believe you asked about the 73 Stage 1 grill badge. It would only have this if the Stage 1 engine was ordered.

Brian, ED,

In 73 Buick separated the GS/Stage 1 package into two separate options, there were 3,933 that had the GS handling package, but only 1,234 had the Stage 1 engine. You could order the Stage 1 engine and not the GS handling package and vice versa. Buick did require one option to get the other, they were separate.

The GS or Stage 1 packages had nothing to do with the interior. You could get a GS/ Stage 1 with the standard interior or the custom. Although I have never seen any GS that had the standard interior, all the one's I've seen had the custom interior.

I hope this will answer everyone's questions. ROA member Rob who is maintaing the Boattail Forum has posted a ton of information. Buick Riviera Boattail 1971 1972 1973

Bob Bonto #277 ROA :)

Technical Advisor 71-73

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  • 1 year later...

Buick used two different cams and were building two Stage 1 engines. According to the letter and documentation that Dennis Manner sent me. The Riviera GS/Stage 1 engine and the Skylark GS Stage 1 both used 1/8" oversize intake and exhaust valves. While the Riviera GS/Stage 1 engine camshaft did have more lift, the Skylark GS/Stage 1 camshaft had significantly more duration for more top end power.

Bob Bonto #277 ROA :)

Technical Advisor 71-73

Bob,

If the engine coded TA (correct 71 Riv GS) is Stage 1 engine, should I use initial timing 10 deg. ? On the label under the hood, it is written 4 deg., but in a 71 book, for Stage 1 is 10 deg..... Of course there is no warranty that I have correct label under the hood - somebody could use repro label over the years.

Any ideas which initial timing is correct ?

EDIT: I was checking also the document: Buick 1971 Engineering Features and AMA Specs © GM Corp , on page 34 it looks like they named Stage 1 only for GS models, while for Riviera GS, something like "higher-powered version of 455". But no mention of Stage 1 in Riviera. Then 4 deg. of initial timing from my label, would be correct.....

post-64271-143138969616_thumb.jpg

post-64271-143138969618_thumb.jpg

Edited by buick-riviera.pl (see edit history)
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  • 1 month later...
What I can't tell from the article or the production figures at the end of the article is this: Could you order the Stage 1 engine and not get the GS package? Were theytwo separate options? You could get the GS option by itself, but to get The Stage 1 option, did you have to order the GS option as well? Perhaps someone will make this more clear.

Ed

It seems we have really opened a can of worms on this subject. So please allow me to try and answer everyone's questions.

Centurion,

Yes Buick used two different cams and were building two Stage 1 engines. According to the letter and documentation that Dennis Manner sent me. The Riviera GS/Stage 1 engine and the Skylark GS Stage 1 both used 1/8" oversize intake and exhaust valves. While the Riviera GS/Stage 1 engine camshaft did have more lift, the Skylark GS/Stage 1 camshaft had significantly more duration for more top end power.

I also believe you asked about the 73 Stage 1 grill badge. It would only have this if the Stage 1 engine was ordered.

Brian, ED,

In 73 Buick separated the GS/Stage 1 package into two separate options, there were 3,933 that had the GS handling package, but only 1,234 had the Stage 1 engine. You could order the Stage 1 engine and not the GS handling package and vice versa. Buick did require one option to get the other, they were separate.

The GS or Stage 1 packages had nothing to do with the interior. You could get a GS/ Stage 1 with the standard interior or the custom. Although I have never seen any GS that had the standard interior, all the one's I've seen had the custom interior.

I hope this will answer everyone's questions. ROA member Rob who is maintaing the Boattail Forum has posted a ton of information. Buick Riviera Boattail 1971 1972 1973

Bob Bonto #277 ROA :)

Technical Advisor 71-73

Hi Guys, New to the Board, I'm sure your assessment is correct Bob, I own one of the few unmolested 1973 Stage 1 Cars and it is not a GS. Stage 1 only with a Standard Interior. Badge on the Grill and Sticker on the Chrome Air Cleaner. I consider it a very rare Car. The car was Ordered that way from Buick as A1 and still designated as a High Performance 455 though I think the Handling Option, H2 was still required with the Stage 1 Package. The H2 Handling could be ordered separate from the GS package and did not automatically make it a GS. GS did not require any other Options but I believe the A1 Stage 1 required the H2 Handling Option I assume because of the raised Horsepower and Posi Rearend. My cleaned up Sticker for info, I do have the Original.

post-86320-143139070115_thumb.jpg

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:)I checked the wholesale order form, you did not have to order the H2 option with the A1 Riviera Stage 1 package. The H2 option. which was the firm ride & handling suspension package only states that it was not available with A9 on the Riviera. The A9 option was the Riviera GS suspension package. I also would like to clarify my January 11, 2011 post, "Buick did require one option to get the other, they were separate."

I meant to say that Buick did not require one option to get the other, both the A1 Stage 1 option and the A9 GS option, were two separate options. My fingers sometimes don't work the same as my brain.

Bob Bonto # 277 ROA

Technical Advisor 71-73

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  • 6 years later...
20 minutes ago, Rivdrivn said:

Can anyone please confirm for me that the engine serial number for a ‘71 is indeed on the driver side between the front two plugs as pictured here? Thanks

A2B9BEFB-0E23-4F4B-A7A3-8679DE511302.png

Confirmed. I have a numbers matching 71 GS and found the stamping there.

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11 hours ago, Rivdrivn said:

Can anyone please confirm for me that the engine serial number for a ‘71 is indeed on the driver side between the front two plugs as pictured here? Thanks

 

 

Steve, I found the VIN on my '72 where Gabriel's top picture shows it, on the passenger side right beside the water pump.

 

On a '71, Gabriel's other picture below shows where it is. In order to see the VIN on a '71, the power steering pump, and bracket, have to be removed. 

 

7 hours ago, Chimera said:

In an area more like these I think. the bottom picture looks most accurate.

Screen Shot 2018-08-20 at 8.35.47 PM.png

 

 

Screen Shot 2018-08-20 at 8.39.05 PM.png

 

Hope that helps ...

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On ‎8‎/‎20‎/‎2018 at 9:13 PM, Rivdrivn said:

Thanks Gabriel. I’m in the hunt. So far we have a TA motor and a GS rust bucket of a body. If they were born together it might be worth buying and eventually restoring.

4223FC92-58FC-42D1-B756-0CF09C9362C8.jpeg

 

Steve, Did you have any luck finding/verifying the VIN on the '71 you were looking at?

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26 minutes ago, Rivman said:

 

Steve, Did you have any luck finding/verifying the VIN on the '71 you were looking at?

No. Long story short, the seller claimed to know a lot about buying and selling collector cars but didn’t believe me that there should be numbers to back up her story that everything was original to the car. I finally convinced her to have someone clean up the engine and look. Eventually she says they found it but she wouldn’t share it with me via text or email. So I said I’d come look again in person. Oh no, let’s talk... I gave up. I no longer believe anything she said, low mileage, original, etc. To me, it’s a parts car with no floors or trunk bed. Looks like it sat in a Georgia swamp for 20 years. Just a shame.

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