A buddy blew his up at 508 after a few months, On3 turbo kit. Now the car has a 298 stroker motor and only makes 490 with the same turbo kit...he's scurrrrred lol
450 is safe for the 3V. I've owned 2 of them, both were supercharged with bolt-ons. My 05 made over 450+ RWHP in hot weather on a non-intercooled setup and was like that for about 3-4 years and 50K+ miles. No issues on the engine.
The thing that kills the 3V drivetrain is torque. Turbo cars or TS cars tend to have more issues than centrifugal cars.