Cars that the average person had, such as the 390 GT Mach I Mustangs,Chevelle SS's with 327's,350's or 396,'68-69 Roadrunners with 383,340 Swingers or Demons,Firebirds with Ram Air III 400's,442 Cutlass's,Buick GS,Camaro's with 350-396,Challengers & Cuda's with 340 or 383.Etc..........
For 1966, they were really fast. Most Big Three cars built in the 1958-62 era were unbelievably bad, slow, crummy cars, so the '63-71 muscle cars were a quantum improvement. However, by today's standards, they are bog-slow. A secretary-mobile Toyota Camry 4-door will blow the decals off a 390 GT Mustang.
One thing to remember is most cars tested by the mags were ringers built by some factory-supported race shop. Pontiac used to have Royal Pontiac put 421" engines in GTOs and send them out for tests. Many times, the showroom stock cars wouldn't get within a second or 10 MPH of the 1/4-mile times they showed in the articles. I remember it well, as I was there, racing them at the time.
One car which hasn't been mentioned is the first big block 396"/425hp '65 Corvette. Want to smoke the tires? With 3.90 gears and Posi, it would smoke both skinny little red-line tires the full length of the quarter. It also blew up with regularity, as GM hadn't figured how to control those long, heavy valves at the 6,500 RPM the solid lifter cam would turn.
Today's Factory-Appearing-Stock-Tire-class cars are a joke I don't get. The faster cars do not have a single OEM internal part. They are running 100-inch billet strokers, custom forged pistons, in pro-built engines, transmissions and suspensions. They are spending $100k to make a forty-year-old car run two seconds and 20 MPH faster than the same car ran when new.
The Pure Stock Muscle Car Drags are the place to go to see what it was really like. There are a couple of certified-stock supercharged '64 Studebaker Larks whipping up on big blocks to the tune of 13.10 @ 105 MPH.
thnx, jack vines