As an engine starts making a lot of horsepower (500 plus) that when the throttle body will really show a resriction. Dyno pulls have been done to prove this. A 500 hp engine will see a 15-17 HP difference between throttle bodies. You might see a little better throttle response, but thats about it. Use the 3 bills on something more worthwhile. Not to say a T.B. isn't worth the cost, just not at this time.