The Grand Marshal is a standard full-sized sedan and is about as muscular as a sea cucumber. I'd classify Bluebuck and Moonhawk as muscle. Reason I argue Moonhawk is because you have to keep in mind, with SAE Net horsepower ratings, a 1973 Road Runner 440 made a whopping 280hp. A Fox-platform Mustang? My dad had a 1985 GT, it made a dizzying 210hp (245 after he was done with it... supposedly). Moonhawk Sport (4 bbl, 378cuin) is ~200hp. I'd classify it as a muscle car, albeit a weak one. Keep in mind: You could get a Charger with a 2bbl 318. The only thing less "muscle" than that is the dang Slant Six. A 1973 Chevelle with a 350 4bbl made 175hp. The 454 4bbl of the same year was 245hp. The base 307 in a 1973 Chevelle Malibu was rated at... are you ready? 110hp. The Malaise-Era fucking SUCKED.