USA vs USA — 1984 vs 1959
| Grand National GNX | Invicta Convertible 401 | |
|---|---|---|
| Horsepower | 276 hp | 325 hp |
| Torque | 360 lb-ft | 410 lb-ft |
| Engine Size | 3,791 cc | 6,571 cc |
| 0-60 mph | 4.7 sec | 8.5 sec |
| Top Speed | 125 mph | 118 mph |
| ¼ Mile | 13.4 sec | 16.0 sec |
| Weight | 3,500 lbs | 4,350 lbs |
| Wheelbase | 2,743 mm | 3,150 mm |
| Length | 5,059 mm | 5,562 mm |
| Units Produced | 547 | — |
| Original MSRP | $29,290 | $3,515 |
| Value (Excellent) | $300,000 | $85,000 |
| Collectibility | 10/10 | 7/10 |
| Rarity | 9/10 | 7/10 |
The 1984 Buick Grand National GNX holds an edge across most measurable criteria, offering quicker acceleration, higher top speed, lighter weight. That said, the 1959 Buick Invicta Convertible 401 brings more power, better value and remains a compelling choice for enthusiasts who value Buick heritage. The right pick depends on whether you prioritize specifications or the intangible qualities that make a car truly special.
Within the Buick stable, the 1984 Buick Grand National GNX and 1959 Buick Invicta Convertible 401 represent different approaches to performance and purpose. Both carry the Buick badge, yet each carves out its own distinct identity. The 1959 Buick Invicta Convertible 401 holds a clear advantage in raw power with 325 hp compared to 276 hp, a 49-horsepower difference that shapes the driving experience. Under the hood, the contrast is notable: the Buick Grand National uses a V6 OHV Turbocharged (Buick 3.8L) displacing 3,791 cc, while the Buick Invicta relies on a V8 OHV (Buick 401 Nailhead) with 6,571 cc. In the sprint to 60 mph, the 1984 Buick Grand National GNX edges ahead at 4.7 seconds versus 8.5 seconds. The Buick Grand National carries a weight advantage, tipping the scales 850 lbs lighter. On the collector market, the 1984 Buick Grand National GNX commands a significant premium over the 1959 Buick Invicta Convertible 401, reflecting differences in prestige and rarity. From a collectibility standpoint, the 1984 Buick Grand National GNX rates higher among enthusiasts and auction houses.