Dodge built the 1968 Dart GTS around a 340 small block, offered a 383 to buyers who wanted more, and flatly refused to put a 440 in the car on its own assembly line. Roughly fifty of them got one anyway, through an outside shop working under Dodge supervision. A clean, documented example is one of the harder cars in the Mopar world to verify. Read on for what to check before you believe the ad copy.