Alot depends on Compression, Stroke, Quality of Parts and Machinework. But IMO over 750 with 2 bolt mains the block starts to become a factor in reliablility, Not that to won't do it, just durability starts to become compromised.
But IMO if you can afford to make over 750hp, you can afford to spend the extra few $$$ On an A460 or Eliminator block.
"durability starts to become compromised"
C'mon, you're producing more power. Durability is not going to increase. We're not talking about a 100,000 mile motor, or even a 10,000 mile motor.
Throwing on studs and a girdle does not prevent cap walk.
It does not take an A460 block or Eliminator to produce four figure hp numbers. If your part selection is not correct for the application, the weakest link will break. So instead of the block giving, the rotating assembly gives and takes out everything, lol.
You guys are correct in that a pure stock, unmodified, block will not take that much power.
You have to do some "work" to the block.