Greeting, I am the new owner of a 1973 Riviera with 62,000 original miles (or so I am told). It's not a GS or stage 1, though I plan on making it a clone with a parts car. I just got it in August 17 and have been reading and studying since. It is a complete, driveable car in desperate need of a paint job and new doors due to rot on the bottoms. It is bone stock with the exception of a Frantz oil cleaner installed by a previous owner. It has also had the AIR pump removed at some point. I have no previous experience with Buicks and am learning all I can. Any recommendations would be greatly appreciated.
Read up on the differences between the term Stage 1 as used for A bodies and the term HP and Stage 1 which applies to E bodies.https://www.hemmings.com/magazine/mus/2016/01/1973-Buick-Riviera-Stage-1/3749308.html
Where would I find this information? I am in a few FB Riviera groups and haven't seen the term HP referenced. I am interested to look into it.
Welcome to the board! Keep us posted and maybe make a build thread for the car in the "Member's Rides" section as you work on it to show us all the progress.
I read the article. It provided a few things I hadn't seen yet and a few I had. I didn't see where you were going with the use of terms for the E bodies. I was aware that for 73, the Stage 1 and GS options were independent of each other.
Thanks. It was an early inheritance for me. It was in the family for several years, but seldom driven. Mostly in storage.
This topic has been discussed on this Board many times. In essence, non A bodies never received a Stage 1 engine. They received another variant of the Buick 455-- the High Performance (HP) engine. Use the search box above.
The hemmings article that you referenced specifically mentioned the Stage 1 engine package. Below is a copy of some of the text from the article. PRODUCTION 1973 Riviera 34,080 GS Option 3,933 Stage 1 Option 1,234
This is a common mistake and misunderstanding. My assumption is the marketing department wanted to use the name "stage 1" on Riviera's because of the good will associated with it since its use on some production A bodies since the 69 model. Buick started producing 455 HPs for some big cars as an option in the 71 model year and continued to use HPs in some non A bodies, including E bodies, through the 74 model year. (I am unsure about the 75 model year.) In the 73 model year someone, most likely in marketing, decided to call what remained a HP engine, a stage 1--thus the confusion.
So what is it that makes an A body a stage 1 variant? In a 73 Riviera, it's the heads, cam, fuel pump, and posi rear end. In the 71 and 72 models, it also included the GS handling package items. If it's the same in the A bodies, I don't see a distinction. I am a member of two Riviera FB pages, one of which is specifically for Boat tails. Everyone there uses the Stage 1 designation as the reference for the higher output 455 and I have never seen one referred to as an HP motor. You may know more about Buicks in general and your car specifically than I do, but we will have to agree to disagree on your point. It makes no sense to use an article to prove your point that has the term you disagree with right in the title.
There are many references, including from the head of Buick power plants at the time, Dennis Manner. Just to kick off some particulars, the camshafts and valves are different. Take the time to look at the Buick parts book numbers. Take a look at the differences in the 71 or 72 wholesale factory order forms--specifically the sales code A blocks. Take a look at the GS Club article posted on this Board referencing the different specifications on the various camshafts used for the 455. The Stage 1 and the HP are not the same. The idea was for big cars to make more torque down low down low due to their weight. This limited their horsepower relative to stage one engines in A bodies. The stage 1 factory ratings numbers were artificially suppressed for A bodies for drag racing factoring advantages.
Welcome to the group, you may want to check out https://www.rivowners.org/ to help with info and parts.....
The 71 model year was the Genesis for the 455 HP but non stage 1 engine option. It was available as an option for the Centurion, LeSabre 455 and Riviera models. The order forms I have do not show it was an option for the 71 Electra or the 71 Estate Wagon. Here are excerpts from the 71 factory order forms for the GS and Riviera. Note the differences in the respective A blocks:
Hi Robert and welcome to the site. While Im certainly no expert on this topic, it has been discussed here on this site many times over the years, and data has been gathered by those that are experts .. as well as discussions with the the gentleman Jim mentioned, Denny Manner, who was responsible for a lot of the development of the 400/430/455 and a few other Buick specific motors - It has been proven that a Riviera badged "stage1" car did not have the same specific engine internals as a GS "stage1" engine for any given year. In the name of making friends and being cordial, it would be prudent to do more research before disagreeing and including others? in your use of "we"
