Ferrari 308 N/A 400 Hp? Really???

[Ferrer]

http://www.ferraris-online.com/pages...=FE-308M-22409

Here it is said that the engine can be tuned up to 400 BHP.....Sheehan is not just somebody, so there might be an element of truth in there.
The standard 308 Michelottos got about 315 BHP with Kugelfisher fuel injection.

I'm not saying I don't believe it, but I'd like to know in which condtions this engine would be producing 400bhp.