Should've included '71-72 GS 350. Some really nice ones have sold for under $15k. https://www.hotcars.com/most-badass-classic-muscle-cars-youll-find-under-15000-today/amp/
Some of their choices are not really muscle cars. That is an overused term. Most are just ordinary cars from the time. Nothing with a slant six was or ever will be a muscle car. My mother owned a 74 Nova with a 350 AC and a two barrel. It was a rugged nice running car but never a muscle car.
I've always gone by the definition that Muscle Car Review devised many years ago. A muscle car was built from 1964 to 1972, has two doors and a V8 of at least 300 horsepower. There are exceptions, of course, such as the 1973-1974 Super Duty Trans Ams. But I think that definition covers 95% of legitimate muscle cars.
The only muscles in some of those cars listed are the ones you would end up using to push them. A lot of those on that list were just a 3 dressed up as a 9.
The article that Phillip linked to recently had the '73 Stage 1 within .1 sec. of the SD T/A in the ¼ mi. IIRC.
