Hot Rod 340 builds and dyno test.
Nice build to prove what you can get from a stock build and what headers could do to add power, but the issues I have with articles like this is, they are comparing their modern dyno to however Chrysler rated them. Secondly the engine was built by a performance shop, not a mass production line where corners are cut, tolerances are loosy goosy, and folks just did their shift.
To make this a honest comparison to other makes, they should spec build the 350 Olds, 350 Poncho, 351 Winsdor and Cleveland, 343 AMC, and 350 Chebby and run them on the same dyno.