RIKIL what year is your 351 is it a roller motor? To get that kind of HP shouldn't be a problem with that supercharger. Put a decent set of aluminum heads on it with a roller cam (E-303 or stage 2 Trickflow) will put you over 400hp with ease. If you are doing a total rebuild you might want to look at strokers 393's or 408's can be had at a very reasonable price. I don't know what kind of boost you are runnig or EFI but you can get over 450hp easily with this kind of set up.