Did clifford say that?
I'm not sure if I'd believe that number, especially doubling the torque. I'm running a Comp Cams 260H and will be adding a Aussie 250 2v head and intake, Headers, and port divider with a Holley 350 and I don't expect much about 120-130 RWHP, which translates to about 150 BHP (manual tranny). If you don't know about the Aussie head (since I notice this is your first post), it is leaps and bounds above the stock head log head.
Now, I would believe that number being close with the Offenhauser 3x1V set up that I ran this summer. It could put out decent power.
Slade