What do you want the car to do? Just saying "I want 350hp" is not going to help you reach any goals of performance. If you want the car to run in the 12's at the strip, then worry about that, not a vague hp number Plus, realize that most of your gains will be done with the chassis, not the motor. Trying to get it into the 12's with stock springs and 3:00 open gears won't cut it. At any rate, you can build a mild 351W that will live day in and day out, put out 350hp with no sweat and be cheaper in the long run than a 350hp, 302 based 347. But before you ever turna wrench, sit down and be honest about what you're trying to acheive with your build up.