What's the complete build on that 396? .010 overbore isn't going to make that power, and if that's the only mod you can list to attribute to 650RWHP, you'll be hard pressed to get anybody to believe that.
I can pass a Porsche in a Chevette. Passing a Porsche means nothing if they aren't racing you.
And if you actually have something with twin turbos pushing 70lbs of boost, you can't be crazy enough to say it's reliable for tens of thousands of miles and more with zero reliability problems IF you're driving it HARD. Not gonna happen.
434 pump gas SBC with an NX/HVH plate system
th350/Coan 5,000 converter/Dana 300 tcase
Dana 30 front with 4.56's/Dana 44 rear with 4.88's