When compiling any list of old muscle cars, there's a certain amount of ambiguity built into the concept. For starters, different experts consider different cars as fitting under the heading of "muscle car." Even a list like "top selling" has its share of wiggle room. For instance, you could be talking about "best selling" at the time they were in new car dealer showrooms. You might be talking best selling over time. It could even mean which of those cars are the best selling today. When you are looking at a whole decades (of course, the muscle car concept essentially died out in the middle part of the 1970's) it gets even more complicated.
AMC was typically not known for making flashy, power strong vehicles. The Javelin was the exception to that rule. Coming with a standard 360-cubic-inch V8, Javelins boasted around 300 horsepower. They have endeared themselves to the hearts of muscle car enthusiasts.
Without question the Camaro is one of the most popular cars ever built by Chevrolet. 1967 was the first year for the Chevy Camaro, as a direct response to Ford's Mustang, and Chevrolet's first entry into what was to be known as the "pony car" market. The 1960's Camaros were the first generation making them particularly attractive to collectors. The 1970 Camaro replaced the boxy design of the first generation with a more European styling. There are those who prefer the 1960's versions, but the 1970's styled cars have their share of fans, too. The 1969 Z28 Camaro in particular is still one of the most popular muscle cars of all time. The Z28 maintained its popularity in the 1970's. A limited production period due to production problems makes this car perhaps a bit rarer than some of the other Camaros. Of course, Chevrolet's focus on new government emissions and fuel economy regulations reduced the power of the Camaro early on in the decade--meaning the earlier ones tend to be more popular.
The Chevelle was one of Chevrolet's most popular models. Not all 60's Chevelles were muscle cars (they even made station wagons) but a Super Sport with a big block V8 was (and still is) a popular choice among muscle car enthusiasts. There were Chevelles that delivered 450 horsepower. If that doesn't qualify as a "muscle car," it's hard to imagine what does. The best selling high performance car in 1968 was the Chevrolet Chevelle SS. With a 396-cubic-inch engine and heavy duty suspension, this car was fast. Still, the new Chevrolet focus on smaller engines later in the 1970's reduced the compression, and power, across the board of its offerings, the Chevelle included.
The first true American sports car, you just can't argue with the Corvette. No matter the year or the model, they just deliver. An American car cut from much the same cloth as European luxury sports cars, it's about as exotic as anything from a major US automaker. They are all collectible, too. 1968 was the first year of the third generation Corvette, designed after the Mako Shark II concept car. That, in itself, makes this edition more sought after than some of the others. The 1960's Corvettes are among the most popular among collectors--even though the 1950's versions might stand a little taller.
While not all Chevy Novas qualify as "muscle cars" the V8 versions certainly do. That is especially true of the 350 cubic inch V8, although, that engine wasn't offered on the Nova after the 1976 model year. You could also say that the 283-cubic-inch V8 fits the bill. It wouldn't be until the 1968 model year that the Chevy Nova Super Sport option would become a performance package, but it was offered as a trim package on the 1967 version.
The 1970 Dodge Challenger was one of the most versatile of the muscle cars. They offered it in a number of different styles and there were 10 engine options. Not all of these really qualify as "muscle cars", but a lot sure do.
The 1968 Dodge Charger was the first model year to feature the "coke bottle" styling. A new sub-type the "R/T" (for "Road/Track") was a high performance version and came standard with a 440 "Magnum" engine, but there was an optional 426-Hemi. You might be familiar with the 1969 Dodge Charger as the General Lee (the car driven by the Dukes of Hazard). There was an optional sunroof package that year, but cars so equipped are extremely rare, as there were only a couple hundred made.
The Ford Mustang is an iconic vehicle like the Camaro and Corvette. When it was originally released it was a design variance of the Ford Falcon. The first model year was 1964. This car has been so influential in classic and muscle car circles that it was the inspiration for the term "pony car." The 1960's era of the car is the one most popular with the majority of car collectors and muscle car fans. While the 1970's versions were different than the '60's models, these cars remained popular, and still are to this day.
1970 saw the introduction of the 351-cubic-inch Cleveland engine to the Mercury Cougar (although the Windsor was also available). The Cleveland is more sought after, and delivered 300 horsepower out of the gate.
The 1967 version of the Barracuda was a Plymouth entry into the "pony car" market. There were a number of engine choices (most of which fit into the "muscle car" category) including a 273-cubic-inch (with both 2 and 4-barrel carburetor choices), and a massive big block 383-cubic-inch V8. The 1967 model was a redesign of the popular platform. With the 1968 Plymouth Barracuda, the 273-cubic-inch engine was gone. Its replacement was a 318. A 340 with a 4-barrel carburetor was offered as was a 383-cubic-inch engine. The most collectible of the 1968 Barracudas were some models built for racing (not street legal) and equipped with 426-Hemi engines. With 11 choices of engine, the 1970 Barracuda had even more power train diversity than the Dodge Challenger. Of most interest to muscle car fans, though, are the bigger engines like the 426-Hemi and the 440 with a "six pack" carburetor.
Plymouth's Road Runner debuted with the 1968 model and it came standard with a 383-cubic inch big block. You could upgrade to a 426-Hemi engine with dual 4-barrel carburetors. This car represented a back to basics muscle car, meaning it was affordable and fast.
Just like its cousin the Chevrolet Camaro, 1967 was the debut outing for the classic Pontiac Firebird. Another in the "pony car" market, the Firebird had a "coke bottle" style. There were a number of engine choices on this vehicle. The 1969 Firebird was the final year of the first generation Firebird design. Interestingly enough the 1969 model year was extended due to production issues with the 1970 Firebird that caused it to be delayed. The Firebird remained a popular car over the years. In fact, the real demise of the Firebird wasn't about the vehicle itself, but rather the discontinuation of the Pontiac nameplate in 2010.
The Pontiac GTO has a legion of fans. It is legendary. Perhaps the most impressive in terms of collectible muscle cars is the 1969 Judge version. One of the most valuable of the muscle cars, the Judge was equipped as a street performance machine extraordinaire, and the car is still popular with collectors today. It was designed with performance in mind and is still very sought after.
When looking at muscle cars, the argument can be made that the muscle cars of the 1960's are the most important. Still, the 1970's models have their fans. It might have been the decade that killed the muscle car, but they didn't go out without a fight. Many of the 1970's models are just as popular as their 1960's peers.