Pristine Riviera GS Stage 1, three owners prior to me, two in Oklahoma and one in Texas. 88k miles. I was able to speak with two prior owners who collectively have knowledge of the entire life of the car. Both reported the car has been well cared for its entire life and always garaged. It is essentially an original survivor in astonishing condition inside and out, evident in the photos and when you drive and see it in person. One of the prior owners did a two-tone repaint. Otherwise the car is original including the factory vinyl top and stunning interior which are mint. Car has the rare optional bucket seats, center console shifter, and factory three-note jazz chord horn.
The 1970 Riviera was a one-year-only body style with a brand new grille design, fender skirts, and swooping side spears. First year for the monster 455 motor, 370 hp, 510 torque, 10:1 compression. These 4360 lb. beasts would do zero to 60 in 7.9 seconds, a quarter mile in 15.1 seconds, and had a top speed of 132 mph. The stock carburetor was a 4 bbl Rochester Quadrajet. Transmission was the Turbo-Hyromatic THM 400.
Of the 37,336 Rivieras produced in 1970, only 3505 were GS (Gran Sport) cars. All GS Rivieras came stock with a 3.42 posi-traction rear axle ratio, tagged as such, self-adjusting power brakes with finned aluminum drums, and a sportier "AccuDrive" suspension featuring special coil springs, shocks, and anti-sway bar. Essentially, the GS option was a ride and handling package and also included a chrome air cleaner lid as an appearance item. Red GS emblems were attached to the front fenders in front of the front wheels, just above the sidelights, not behind as in previous years. There was no Riviera script on the fenders and no GS emblems used on the dash.
Stage 1 Option
From researching many Buick Forum sites and studying the original 1970 Buick specs literature, all 1970 GS Rivieras were essentially Stage 1 "High Performance" motors, though not designated with Stage 1 emblems. (Stage 1 badging was not installed on GS Rivieras until 1973). As you can see in the photos, my Riviera GS has Stage 1 emblems added to the grille and air cleaner, done by a prior owner. No harm no foul, they look cool and actually are descriptively correct.
The 1970 Riviera 455 GS produced 370 hp at 4600 rpm, higher than its muscle stablemate, the mid-size Buick Gran Sport Stage 1, which produced 360 hp at 4600 rpm. All '70 Riviera 455 heads were machined differently to accompany the larger valves, and included unshrouding the valves for better flow. They incorporated a different cam shaft. These characteristics gave them the "High Performance" description used in Buick literature. The motors were coded with a SS prefix to the 1231786 casting number. (Standard 455's were coded SF).
Mechanical work over the last several years:
- New AC compressor, dryer, evaporator, freon converted to R134
- New electronic ignition
- Newly rebuilt Rochester Quadrajet carburetor
- New drive shaft
- New alternator
- New tires and shocks
- New transmission pan
- New duct work and vacuum lines behind dash
- New window motor and PDL switches and wiring
- New weather stripping, doors and trunk
- Recent full tune-up and all new fluids
- Engine bay and undercarriage professionally reconditioned and detailed
- All panel gaps are straight
- I give the body/paint 7 of 10
- Original vinyl top virtually flawless
- All chrome still shiny, no pitting or fading
- All stainless moulding and rocker trim very nice
- Chrome side spears, the most expensive option (most spears were painted)
- All glass excellent, one small windshield chip repair
- All rockers, doors, jams, floor pans, and trunk pan are solid
- Trunk is clean, fifth Buick Rally spare, original jack
Near perfect dash pad, door panels, factory bucket seats, headliner, and package tray. No rips, cracks, or tears anywhere, the only exception being a small hole in the headliner partially hidden behind the passenger sun visor. Rare center console floor shifter with storage compartment is pristine with no scratching or marring. Original cut pile carpet well preserved, little wear. Original AM/FM radio is intermittent, crackles. All interior lights, signals, switches, gauges, and environmental controls are functional except clock. R134 AC blows cold. Tilt steering, PS, PB, PW, PDL, and Power drivers seat all functional.
The 1970 Riviera GS is a definite sleeper in the personal luxury muscle category. Values are heading up, now's the time.
CONTACT ME FOR A LINK TO MANY HIGH RESOLUTION PHOTOS !!