USA vs USA — 1970 vs 1978
| AMX 390 Big Bad | Concord AMX | |
|---|---|---|
| Horsepower | 325 hp | 140 hp |
| Torque | 425 lb-ft | 270 lb-ft |
| Engine Size | 6,391 cc | 5,898 cc |
| 0-60 mph | 6.6 sec | 11.5 sec |
| Top Speed | 130 mph | 103 mph |
| ¼ Mile | 14.4 sec | 18.0 sec |
| Weight | 3,300 lbs | 3,300 lbs |
| Wheelbase | 2,794 mm | 2,743 mm |
| Length | 4,877 mm | 4,826 mm |
| Units Produced | 4,116 | 2,540 |
| Original MSRP | $3,395 | $5,899 |
| Value (Excellent) | $65,000 | $28,000 |
| Collectibility | 8/10 | 6/10 |
| Rarity | 7/10 | 7/10 |
The 1970 AMC AMX 390 Big Bad holds an edge across most measurable criteria, offering more power, quicker acceleration, higher top speed. That said, the 1978 AMC Concord AMX brings better value and remains a compelling choice for enthusiasts who value AMC heritage. The right pick depends on whether you prioritize specifications or the intangible qualities that make a car truly special.
Within the AMC stable, the 1970 AMC AMX 390 Big Bad and 1978 AMC Concord AMX represent different approaches to performance and purpose. Both carry the AMC badge, yet each carves out its own distinct identity. The 1970 AMC AMX 390 Big Bad holds a clear advantage in raw power with 325 hp compared to 140 hp, a 185-horsepower difference that shapes the driving experience. Under the hood, the contrast is notable: the AMC AMX uses a V8 OHV (AMC 390) displacing 6,391 cc, while the AMC Concord relies on a V8 OHV with 5,898 cc. In the sprint to 60 mph, the 1970 AMC AMX 390 Big Bad edges ahead at 6.6 seconds versus 11.5 seconds. On the collector market, the 1970 AMC AMX 390 Big Bad commands a significant premium over the 1978 AMC Concord AMX, reflecting differences in prestige and rarity. From a collectibility standpoint, the 1970 AMC AMX 390 Big Bad rates higher among enthusiasts and auction houses.