No chassis failure probs.. Broken diffs, and halfshafts yes..

But with that kind of hp, most guys will have modded the rest of the car to support that kind of hp. That requires rollbar/ or cages, engine braces, BRAKES, suspension, shocks/spring rates.

4-500hp is A lot of hp for a 20+ year old unibody. Best case senario, is slowly your car will start to rattle, groan, doors not seal proper, and wheel alignments will get difficult as the chassis sees more and more twisting/wear and tear....

That kind of hp takes more thought than just motor...

I'm running the kind of #'s you speak of.. and I have a full cage, huge brakes, upgraded suspension, lots of bracing etc...
I can still jack my car up and get 3 wheels off the ground and still open my doors perfectly... big deal.. well maybe, when you see how hard I drive this car sometimes.. slalom, road courses, drag strips etc..

Good luck.

 

You will hurt the car over time, there are wrinkles in first gen Camaros for this reason.

Get a cage and strut bars.

 

its a good idea to reinforce your frame rails I have heard of a few guys here in cali cracking them and pulling the front apart with the high horsepower I6 and the V8 just something to think about.