Real Horsepower of Muscle Cars

I have an old magazine around here somewhere that had an article called "Putting the Bull behind the Horses" about this very subject. They took engines that were apparently (based on compression, valve lift, etc) stock and dynoed them. The only numbers I remember were as follows:

MOPAR

340 - 305HP
383 - 355HP
440+6 - 415HP
426 Hemi - 535HP.

Chevy

427 tri-power - 465HP
302 Z Block w/ crossram - 295HP

Ford

427 Side oiler W/ 2 4bbl - 460HP
428 CJ - 395HP

Were they truly stock? Who knows?