Depends what fuel you can get in your country.

In this country on the shonky fuel we get, then I would say 360ish is the limit. In the days of decent fuel I got an engine dyno confirmed 385bhp (backed up by Datron confirmed 172mph and a 12.64 @ 115mph quarter). If you can get the Shell V-max 100RON then nigh on 400bhp might be possible.....