The optional engine package included a chromed air cleaner lid without a decal

In previous issues we covered the 1965 through 1969 Gran Sport/GS options. In this the last of the three part series we will cover the 1970-1975 models. Once again we remind you that these options do not include interior trim, bucket seats, chrome wheels. These and other options are separate and available on every Riviera

1970 GS

The new 455ci engine was introduced in 1970 and was installed in the restyled body of the 1970 Riviera. This new look included exposed headlight for the first time since 1964 and fender skirts for the only time on a Riviera. The shirts were available in full or short styles. Another option was a wide spear that ran along the side bodylines. The 1970 was in many ways a one of a kind design, however when it came to the GS option it was just a ride & handling package, with a posi rear and an axle ratio of 3.42. Only one engine was available for the Riviera in 1970, but what an engine! The first 455 ci had the highest recorded horsepower rating of any Riviera ever made. According to Buick's figures it was rated at 370hp. The GS option did include a chrome air cleaner lid as an appearance item for the engine. Otherwise the engine remained unchanged. Based on Buick literature the engine was a Stage1, however the name was not used for the Riviera in 1970. The red GS emblem was attached to the front fenders, in front of the front wheels, just above the sidelights, not behind as in previous years and there was no Riviera script on the fenders of the '70. Despite what some Buick literature states there were no GS emblems used on the dash.

1971-1972 GS

The GS option in these two years were very similar in that an modified engine was part of the package, which offered an additional 10-15 hp over the standard engine. Once again the chromed air cleaner lid was included. Beginning with the '72 model the vin# included the letter "W" to indicate that the car was equipped with the optional Stage 1 engine. As in '70 there was no additional Stage 1 decals or emblems on the car. The GS option included the engine a well as the ride and handling package and posi rear axle with a 3.42 ratio. The fender emblems changed once again with a return to the Riviera script located behind the front wheels. The script had a new sleeker look for the first time. The red GS emblems, similar to the one used from 67-70, were positioned below the script rather than behind, as in previous years.

1973-1974 GS/Stage 1

The Stage 1 engine option in 1973 was identified by the badge in the grill

Beginning with the '73 model the Stage 1 emblem was first used to identify the optional engine package. The Stage 1 badge was attached to the grille, as shown in the photograph. AS in 1972 the letter "W" appears in the vin # to indicate that the car was equipped with the Stage 1 engine. Once again the only difference in the appearance of the engine was the addition of a chromed lid on the air cleaner, with out any decals. During these years the GS option was a ride and handling package only.

Now that the GS was replaced with the Stage 1 as the engine option, Buick changed the color of the GS emblems to gold rather than the traditional red. The Stage 1 package included the modified engine, chrome air cleaner and a posi rear with an axle ratio of 3.23. If the car were equipped with both options it would have both emblems. There were only a limited number of cars built with both option. (see production figures at the end of this article) Although radial tires had been available for several years they were first included in '73 as part of the GS package.

1975 GS

The GS emblem was placed beneath the Riviera script in '71 - '75 models

The optional Stage 1 engine was no longer offered in the Riviera, but the GS ride and handling option was continued into the new model year. Only the standard 455 engine was available. As in the 1973-'74 models the GS emblems were positioned below the script on the fenders and painted gold rather than red.

"The GS/Stage I options do not include upgrade interiors!"

Summary
Be suspicious of overly chromed engines, since the standard 70-74 GS/Stage1 engines had only the chromed air cleaner lid. Buick did offer a dress-up appearance package with the chromed lid and chromed value cover, but that did not make it a GS/Stage1. Similarly additional engine decals may have been added to dress up an engine. If you have any questions about your car, or one you are looking to purchase, don't hesitate to contact the ROA office/library or the tech advisor for your year. It may just save you some money!

Production Figures