OK, here's the crux of the story. The bottom head is a virgin '64 Stage III Max Wedge 518 casting. It's worth about two grand. Notice how much larger the intake ports are compared to our standard 452 wedge casting. The Maxie's exhaust ports are also about 20 percent larger. But it's an established fact that an untouched 452 head can legitimately support 1 hp/ci. We're here to say the standard wedge head is plenty good for hot street and strip use. Notice the Maxie's lack of a heat crossover passage.