hmm...i know that by 1974, the 440 was long gone from the challenger, but the charger still offered in it 74...it was a bit watered down, to 280 hp, but it is still a buildable 440...any 440 is a good place to start, but finding out what it came from will tell you how potent it was stock...for instance, the 440 found in trucks in 1974 would have only been 235hp