With BPU and a FMIC my '96 TT6 made 420 at 1.2 bar on the rolling road at a TVR vs Supra shootout at the place near Gatwick (the name escapes me). I reckon with a decent SMIC, like a CW one, it would make about the same.
It was an absolute animal (not as much as the big singles but a handful none the less) and it really would play with the big boys and would quite happily spin the rear wheels in 4th it you gave it a boot-ful. I had it like that for about 7 years until my wife stacked it. But nothing really went wrong with it as I stayed on top of the services and replaced things like the coil pack connectors.
It's a totally different car once BPU. But as others have said, if you're not prepared to deal with stress causing issues then don't push it too much.
Has it done a load of miles?