Well, it really depends on how you drive it and how lucky you are. I've seen guys here that have 400+hp 355's in front of them drag racing all the time and they last fine, yet I've also seen guys that are running stock low output motors that blow them. Like I blew my NWC T5 behind my almost stock LG4, now I have a WC T5 and it's doing fine, but we'll see when I get the motor back in, should be sitting around 300hp or so. If you know how to drive a stick (I do, I just don't have much luck with car parts) and don't abuse it (I never really abused mine, but it blew anyways, I think it was just luck though, nothing to do with how I drive it) it will last. Also, the way to save them is not hooking, so no slicks at the track, only radials and power shifting is definitely not reccomended unless you want to replace parts. So in short, I don't think there's really a number on them, it just depends on how it's driven. Heck you could probably make one last behind a 500hp motor if you were really nice to it, but that wouldn't be any fun would it???
