if you're serious about GN turbo 6 power, see Kenny Duttweiler, here's why

It started out that if you could make 600 hp on the dyno, everybody was ecstatic—they couldn’t believe it. Then a year later, it was 1,200 hp and 20 years later or whatever it’s 1,900 hp. I’ve got one on the stand right now that made 1,930 hp.

That’s from a 265ci V6 engine. The evolution is interesting because I started out with a stocker that made 200 hp and then we just kept adding better turbos and better everything.

http://www.hotrod.com/features/1502-take-5-kenny-duttweiler/