These cars are exceptional though, and not the norm. the 260bhp one you speak of is TingTongs, he works there, and the WMI allows LOADS of timing to be added. Special cars indeed compared to those you drive around in every day.
Also, a ko3S at 250bhp won't last very long at all.
Sensible figures are 230-235bhp and 270lbft, they can produce this year in year out and don't fall apart. Anything more than that and you've created a time bomb.