"Muscle Car's" are typically defined and thought of by most as being the vintage classic hot rods of the 1960's through 1970's. Such as the Plymouth Duster, Chevy Camero, Pontiac GTO, Ford Mustang, Shelby Cobra, Dodge Challenger, Dodge Charger, and a few others. Some that aren't considered muscle car's of the 60's-70's might surprise most...such as the Chevy Corvette isn't defined as a muscle car. At one time I owned a 66 Mustang, and a 72 Plymouth Duster, both now defined as Muscle Car's...wish I'd kept both too! LOL Use to drag race the Duster out on the local straightaway, as the majority of HS and young adult age's did in our area, hahaha.
These are the official definition's of 60's-70's "Muscle Car" as defined by the MCCA:
Strict Definition of a Muscle Car:
A muscle car, by the strictest definition, is an intermediate sized, performance oriented model, powered by a large V8 engine, at an affordable price. Most of these models were based on "regular" production vehicles. These vehicles are generally not considered muscle cars, even when equipped with large V8s. If there was a high performance version available, it gets the credit, and not the vehicle that it was based on.
Examples: Buick GS, Chevrolete Chevelle SS, Dodge Charger R/T, Ford Torino/Cobra, Plymouth GTX, Plymouth Road Runner, Oldsmobile 442, Pontiac GTO
Fullsize Muscle Car:
The strict definition only includes intermediate size vehicles. In reality, performance oriented intermediate size vehicles didn't appear until 1964. Before then, manufacturers took existing fullsize vehicles and added extra performance to them. Because of this, the early fullsize performance vehicles are generally considered muscle cars.
Examples: Chevrolet Impala (SS only), Ford Galaxie (with 390 + cid engines only), Dodge Coronet (R/Ts only), etc.
Pony Cars and Compact Cars:
In addition to fullsize and intermediate muscle cars, a number of smaller vehicles started appearing on the automotive performance scene. These new "pony cars" and compact cars are generally considered muscle cars only if they have the top of the line performance engines and options.
Examples: Chevrolet Camaro (SS and Z28 models only), Ford Mustang (GTs and Boss only), Plymouth 'Cudas (no Barracudas), AMC Javelin, etc.