It depends on a LOT of things, honestly.....
My old 2.0 I built for my Talon with an Eagle/Wiseco combo made 466 on 91 pump gas and a 62-1 back in '06. I did a mix of beating the piss out of it and DD'ing for almost 2 years before I sold it. Then, the guy I sold it to sold it to a HS kid who totalled it, and a couple local DSM buddies went to the junkyard and pulled it apart. The head is happily on top a 790WHP Talon, and the bottom end is happily in a DD'd 1gb 50 timmed Talon that goes between CO, NY and CA a few times a year. Last I'd heard the head is still working just fine, but MAY need new valve seals, and the bottom end is still going strong, never missing a beat, using oil or leaking. This is all after almost 7 years(DAMN TIEM FLIES!!)of not the most ideal conditions and so-on.
My only point, is it all depends on who does the machine work and assembling of the engine as to how well it's going to work and how long it's going to last. You really need to do your research as to which setup you want, your power goals, and finding a local machinist/builder taht has a reputation good enough to build an engine that's going to last AND perform.
An engine will only last as long as it's built to.
Hope that helps, GL!
-Jake