limits of drivetrain/powertrain (with mods)

I was wondering about what the limits are for the stock parts (99 f250 V10, 4R100) with mods, that is, should anything be reinforced or replaced? For example, I heard that the stock trans can handle 450 lb-ft, but with superchip and say a gale banks powerpack, that's already exceeded.. especially with a supercharger.. I'm just suspecting that stock parts usually don't have too much tolerance like the f150--to convert to the Lighting, super duty compenents like transmission had to be used (for reliability, which is what I want).

[ray]