* Stock: A stock 1970 Dodge Charger R/T with its 440 cubic inch V8 would generally be faster than a stock 1967 Mustang GT.
* Modified: Since "Eleanor" is a heavily modified movie car, its performance can vary wildly depending on the build. A highly modified Eleanor could easily outperform a stock, or even mildly modified, 1970 Charger. Conversely, a heavily modified Charger could easily outpace a less-modified Eleanor.
Therefore, there's no definitive answer without knowing the specific engine and modifications of each individual car.