Tony,
I think stroaking a 351 out to 427 is pushing it. I have mine at 416 and a friend has his at 410, but most of the people have them in the 396 range and have no problem getting 500+ horsepower. When I had mine built it was originally going to be over 600 horse but I changed my mind and now I wish I had even gone to around 450 horse instead of the 530-550 that I have. I drive mine on the street and my friend had his built out to quite a bit more power than I have and he wishes he hadn't now. Talk to the guys with the ones in the 396 range and they can tell you more.
Ron "")
