That's hard to comment on. I've heard some guys from the F-body forums with no problems with LT1's with over 100k miles, then others from problems almost right off the bat.
If driven responsibly, which I don't think I could really do myself, you luck should improve.
Now, most companies and reliable shops say the bottom end of the LT1 should be fine with 6lbs of boost. Eventually you will probably need to rebuild the motor because the added stress on a boosted motor will lead to parts wearing out sooner.
Ideally, you will want to build the motor with a lower compression ratio, maybe in the 8.5/9 to 1 range, with forged components made for superchargered/turbo motors. Then you can really crank up the boost and feel confident about your motor. You'll also want a custom grind camshaft for your specific application. A big lopey camshaft will not help out a boosted motor.
When you reach the point and get serious about the whole package, call a few different shops that have charger/turbo experience. The ideal companies you have this experience PLUS experience with Vettes or chevy motors. When you can talk to a shop with real world experience, they can give you all the in's and out's and what you should/can expect.
If you want to go the charged route, which is exactly what I want to do myself, you can get away with the ATI kit alone and should be pretty safe. You should plan on building a motor eventually.
Hope this helps out a bit.