I suspect i will get flamed for this but here it goes:
Actually a lot of the old muscle cars when stock could barely break 7 sec 0-60, or 15sec 1/4 back when they were new ( with a good driver and abusive clutch dropping)
A lot of the published times in those days were manuafcureres ringers.
Yes they responded well to mods and a lot of them are very fast.
But these are the "good old days" of performance right now.