Strong Block

Anyone know where I can get a good solid 4.6l SOHC forged block? I am looking into doing a twin turbo application and hoping to eventually put up numbers in the 600+ range, any 4.6l SOHC blocks that can safely handle that out there?

Aftermarket 4.6 blocks I believe can be bought from ModMax, Hyland Motorsports etc.., There are other that I can't think of right now.. Also if all you looking for is around 600hp no need for twin turbo. They are gettin 600hp easily out of 4.6 motors with a single turbo set-up(ahhh the beauty of a V-8 shows once again).

I am not really looking to limit myself to 600HP, that is just a number I kind of threw out there. I am slowly going to build up a 4.6l SOHC twin turbo, while in the meantime doing mods to my '01 GT to prepare it for the engine. The main thing I am trying to do though is keep it street legal, no point in having a bad ass car if you can't drive it around town to show it off. I would be more than happy to hit numbers higher than 600 if my setup allows.