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What is a Gran Sport/G.S./Stage 1? (Part 2)

By Darwin Falk, ROA #2077 & Ray Knott ROA #1

This article is re-printed from, "The Riview", published by the Riviera Owners Association

In the last issue of the Riview, we covered the 1965 Gran Sport option. This segment will continue with information on the 1966-1969 GS. As mentioned earlier the GS is an option not a separate model, therefore the vin # will not identify the car as being a GS (except in 72-74 models). Once again we must repeat that the GS option does not include interior trim, bucket seats, chrome wheels, etc. These upgrades are separate and available on every model.

1966 G.S. (A-9 option)

1966 Emblem

As in all years the quickest way to identify a GS is the exterior emblems.. 1966 was the first year that Buick use the GS abbreviation on the Riviera rather than having Gran Sport spelled out as they did in '65. The red GS emblems that were attached to the front fenders were in large block form (unique to the '66 models). The GS letters on all 66-69 models follow the Riviera script on both sides as in "Riviera GS".

If you ever see "GS Riviera," it is incorrect. It's true regardless of what side it's on. There were no GS emblems used on the rear of the 66-69 models, unlike the '65 models. In 1966 the words "Riviera GS" appeared on the wood trim attached to the glove box door. The letters are in a block style like those used on the fenders. Despite what some dealer brochures listed this was the last year that the GS marking appeared in the interior.

1966 GS air cleaner on 1-4bbl. carburettor

The only engine offered in '66 was the 425ci (code MW) with a single Quadrajet carburetor. The engine code is located on the top front lip of the engine block, as pictured on page 13 of Vol. 17-3. If the GS option was ordered the standard black air cleaner was replaced with a large single snorkel chrome air cleaner, similar to the one used in the '64 model. The valve covers were the finned aluminum valve covers with "Buick" in raised letters.

Although they appear to be the same as the ones used in earlier models, there is a "dent" at the front of the drivers side cover. This indentation gave extra clearance for California emission- equipped cars that had an AIR (smog) pump in that area.All 66 models had the "dent" even if they were not California cars. If the buyer wanted the dual 4 bbl option it could be ordered from the dealer, but the engine would still have the "MW" code. Starting in March of '66 the dual 4 bbl was available from the factory. If it was ordered from the factory the engine was stamped with a "MZ" code. Only 179 Rivieras were ordered with the "MZ" code. In 66 the "MX" code was used on a 340 ci V-

1967 Emblem

8.The air cleaner for the dual 4 bbl setup was the same large chrome double snorkel as was used in '64 & '65. An engine dress up kit consisting of chrome valve covers and air cleaner was available but not part of the GS option.

The transmission was the same as the modified option offered in 1965, with a "BS" code on the I.D. plate. All 66-75 GS models had a positive transaction differential and heavy-duty suspension. The 3.42:1 axle ratio was standard on the GS. Buyers of the '66 GS had the choice of 8:45x15-2 ply tires with a 4-ply rating in either white walls or red line. A faster steering option (C-5) with a 15:1 ratio was not included, but available for extra cost.

1967 "Star Wars" air cleaner

The exterior emblems were attached to the front fenders and followed "Riviera" as they did in '66. The GS letters were red, but unlike '66 they had a stylistic slant, and were not block style. The '68 and 69 models changed the style of the "Riviera" on the fenders from the script style to block letters (but the GS emblem was the same used for 1967). There was no GS emblem on the rear deck, and despite what dealer brochures list, there were no interior emblems. Buick no longer used "Gran Sport" even in their brochures, it was just GS. As stated above, the interior was not part of the GS option. The new 430ci engine was introduced in 1967 and was standard on all Riviera models for the next three years. This was the only engine available and was used in the GS option as well. The engine code on the 430 was located on the right side of the engine below the spark plugs. In '67 the air cleaner was an unusual red double snorkel fiberglass style, commonly known as the "Star Wars." The only difference in the 68-69 GS engines was that the lid of the standard air cleaner was chromed. This chromed lid was also available on any model as a dealers option.

1968-'69 Emblem

The GS option also included a heavy-duty suspension and a 3:42:1 axle ratio positive traction rear. Buyers of the 67-68 models had a choice of 8:45x 15 whitewalls or H-70-15 wide oval red line or whitewalls. Beginning in January of 1967 radial ply whitewall tires (225-R-15) became an extra cost option for all full sized Buicks (radials were also available for the smaller model Buicks) In 1969 a fiberglass belted whitewalls (J-78-15) also became available. In '67-'68 the faster 15:1 ratio steering was available, but not included in the GS package. The fast ratio steering will turn lock to lock at 3.25 turns versus the standard 3.75. Beginning in '69 all Riviera models had variable ratio steering, so there was no separate GS steering option.

Production Figures

Year Total Production GS Engine codes
1966 45,348 5,718 MW or MZ
1967 42,799 4,837 ND
1968 42,284 5,337 PD
1969 52,872 5,272 RD


Notice: BUICK and RIVIERA are trademarks of GENERAL MOTORS CORPORATION used with permission. The Riviera Owners Association is independent and not affiliated with GENERAL MOTORS CORPORATION or its BUICK MOTORS DIVISION    —Copyright 2007 Riviera Owners Association—