302/351 Ford OE blocks - how to make them live even at 1000 hp

In this, episode 67 of PowerTec 10, DV looks into the problem of block breakage when making more than about 450 HP (302). These engines are cable of over 600 HP as an atmo motor and well over 2000 hp in turbo form.
Granted most of us won't be in the range of stratasferic turbo numbers but many potentially good build specs will put a 302 over 500 hp so we need to know how to make it good to 600 +. It's easier than you might suppose because the blocks don't break for quite the reasons you may think!