Why are 2JZ-GTE engines famous for handling 1000+ HP?

The 2JZ-GTE has a closed-deck cast iron block (vs open-deck on most aluminum blocks), forged steel crankshaft and connecting rods, and strong main bearings. These construction details make the rotating assembly more resistant to extreme cylinder pressures. With proper head studs, the factory block and internals can reliably handle 900-1,100 HP on pump gas.