USA vs USA — 1970 vs 1967
| AMX 390 Big Bad | GTX 440+6 | |
|---|---|---|
| Horsepower | 325 hp | 390 hp |
| Torque | 425 lb-ft | 490 lb-ft |
| Engine Size | 6,391 cc | 7,210 cc |
| 0-60 mph | 6.6 sec | 5.2 sec |
| Top Speed | 130 mph | 130 mph |
| ¼ Mile | 14.4 sec | 13.5 sec |
| Weight | 3,300 lbs | 3,800 lbs |
| Wheelbase | 2,794 mm | 2,946 mm |
| Length | 4,877 mm | 5,258 mm |
| Units Produced | 4,116 | 2,035 |
| Original MSRP | $3,395 | $3,733 |
| Value (Excellent) | $65,000 | $175,000 |
| Collectibility | 8/10 | 9/10 |
| Rarity | 7/10 | 8/10 |
Numbers favor the 1967 Plymouth GTX 440+6 with more power, quicker acceleration, greater rarity. The 1970 AMC AMX 390 Big Bad offers lighter weight, better value, and has its own devoted following. For those who let their heart decide, either car delivers a rewarding ownership experience.
In the world of Muscle Car cars, few comparisons generate as much discussion as the 1970 AMC AMX 390 Big Bad versus the 1967 Plymouth GTX 440+6. Both hail from Muscle era and represent the pinnacle of their respective manufacturers' ambitions. The 1967 Plymouth GTX 440+6 holds a clear advantage in raw power with 390 hp compared to 325 hp, a 65-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 Plymouth GTX relies on a V8 OHV (440 Six Pack) with 7,210 cc. In the sprint to 60 mph, the 1967 Plymouth GTX 440+6 edges ahead at 5.2 seconds versus 6.6 seconds. The AMC AMX carries a weight advantage, tipping the scales 500 lbs lighter. On the collector market, the 1967 Plymouth GTX 440+6 commands a significant premium over the 1970 AMC AMX 390 Big Bad, reflecting differences in prestige and rarity.