1970 Buick Skylark GS
A-body · New 455ci engine. Stage 1 package produces 510 lb-ft of torq... · The gentleman's muscle car — Stage 1 455 is one of the most torquey engines ever built
Highly Collectible
Production & Overview
Total Production
23,007
Original MSRP
N/A
Assembly Plants
Flint, MI · Fremont, CA
Wheelbase
112 inches
Body Styles
2-Door Hardtop · Convertible
Curb Weight
3,830 lbs
Notable Packages & Production
Stage 1 455 — Stage 1
3-4x base
8,732
produced
GSX Package — GSX
6-10x base
678
produced
Available Engines
350 350ci — V8
Base GS engine
260 hp
Stage 1 455ci — V8
Stage 1 — 510 lb-ft torque. Factory underrated. Most torquey stock American car.
360 hp
Buyer Checklist
⚠ Clone warning: GSX non-matching loses 70%+. Stage 1 non-matching loses 55%.. Always verify with cowl tag, engine stamp, and registry before purchase.
Decode cowl tag for Stage 1 and GSX option codes
GSX — verify Saturn Yellow or Apollo White paint (only colors made)
GSX spoilers — front and rear are correct and original
Check engine suffix for Stage 1 designation
Inspect A-body floor pans and frame rails for rust
Verify correct 455 vs 350
Look for build sheet under rear seat
Check rear axle ratio for Stage 1 verification
Road test: Stage 1 torque is immediately obvious
Verify correct stripes on GSX
Known Problem Areas
GSX fraud — most common Buick muscle fraud
Stage 1 fraud on standard 455 cars
Floor pan rust
A-body lower quarter rust
Engine oil leaks — 455 common after 50 years
What Drives Value
↑ Increases Value
GSX Stage 1 in Saturn Yellow or Apollo White — documented
Stage 1 convertible — fewer than 100 with Stage 1
Numbers-matching Stage 1 with cowl tag
GSX with full documentation
↓ Decreases Value
GSX fraud
Stage 1 fraud
Non-matching engine
Heavy rust
Restoration Overview
Difficulty
Medium
Parts Availability
Good — strong A-body reproduction market
Driver Quality Cost
$22,000 – $45,000
Show Quality Cost
$55,000 – $120,000
Key Suppliers
Ground Up SS · OER · Buick Club of America vendors
Pop Culture & Legacy
Stage 1 455 produced 510 lb-ft torque — unprecedented for a street car
GSX Saturn Yellow is one of the most visually striking muscle cars ever made
Consistently undervalued vs GTO and Chevelle — growing appreciation
Other Buick Skylark GS Years