What Are These Access Holes For In The Sides Of My 440 For??

That system was originally mandated in '68 on the 385ci Chrysler big blocks under the Cleaner Air Act, it's the PCV setup, or Permanent Crankcase Ventilation system, and is designed to keep unburned hydrocarbons from building up in the block.

The released hydrocarbons are trapped under the hood, diluted with the incoming air from the fan and then pulled back in through the carb and burned. This system also greatly reduces oil leaks at the gaskets and seals caused from blowby past the rings pressurizing the block internally as the engine ages.........