The GTO can't take credit for starting the pony car era; that honor belongs exclusively to the Mustang, which started the long hood/short rear deck craze. That's why they are called "pony" cars, after the Mustang.
You are correct that the other big-block sedans pre-dated the GTO, but they weren't marketed as perfomance cars and you could buy them with basic engines. The GTO had a big-block, period, and no persona other than as a muscle car. That's why it's considered the first.
Ken, the problem with those earlier models is that the big-blocks were a check box on the option sheet of a model that could be had with a 6-banger. They also didn't get much marketing in the big-block trim, either.
I would agree that, in terms of power, they were muscle cars. But the industry has generally come to accept the GTO as the first pure muscle car because it couldn't be had as anything else and was only marketed as a performance car.
There's lots of room for differing opinions on this one, though!
Before the mid-sixties, cars that 'went fast, cost little' were called supercars. It's around the time of the GTO and Mustang that the name Muscle car came about and replaced the little used supercar moniker. However, "High performance at low cost" was still the driver and the easiest way to do that is stuff a big engine in a smaller car.
Because the Hornet qualified on all counts (and went on to do well at NASCAR too), the Hornet is the great, original muscle car. And it had a six (beating many V-8s of the era).
there were big block cars BEFORE the introduction of the GTO.. HOWEVER the GTO was the first car " marketed" as a muscle car , or performance car aimed towards those buyers. they always dub the GTO " the first muscle car " on documentarys and such . im personally not a big fan, except maybe the judge, those were ok . but still too much of a boat for my liking.... people always talked about the goats as being brute performers, but i always read up on stats and comparisons and such, and the goats never actually seemed to place very high when compared to other cars of that era .
I hear what you're saying. However, the GTO was simply a Tempest (which originally had a 6 cyl, and later a smaller V8), so I don't see that much difference. I owned a 1965 GTO 389 4 BBL, 4 spd, and a 1969 Tempest with a 350 2 bbl, auto. The only difference between my 1969 Custom S Tempest and the GTO was the engine and some badges.
I was lucky to grow up during this era, and can remember seeing the 409 Chevy's blast down the strip. We had a car club in our town (the Galahads) that operated a drag strip every Sunday. It was open to anybody who wanted to run (no charge), and was used for some sanctioned NHRA events. Anybody who ever saw some of the 409's performing there has to consider them a muscle car. Most fun I ever had with my pants on! ::
Oh Yeah, I forgot to put on my list the 1962 Pontiac 421. That was one screaming MF when set up right.