Yes, it would certainly appear that way.
But also keep in mind you're not only limiting your 'class' to naturally aspirated, but also pony cars.
There are certainly more powerful pony cars, and more powerful N/A applications.. just when the two are teamed together you get *for now* the most powerful application....
Though, I would be inclined to guess some of the 64-70 era pony cars were RIGHT on the edge of a modern 500-550 hp rating...
2013 GT500- Grabber Blue/stripe delete, Base, Recaros,
1999 GT- Atlantic Blue, gears, exhaust, tires 13.6@100
1972 Mach 1- Med Lime Green Metallic, 351-4V, auto,