There's no single definitive answer. However, a well-maintained 1970 Dodge Charger with a high-performance engine like the 426 Hemi might achieve a top speed in the 130-140 mph range, but this is an estimate and is not guaranteed. Lower-powered 8-cylinder models would have substantially lower top speeds, possibly in the 100-120 mph range, again, depending on the factors listed above. It's important to remember that these are theoretical maximums and achieving them safely is unlikely and highly discouraged.
