I agree on the HP, but what does the torque curve look like for both engines. I'll bet the straight 6 and the 283 make more natural low end torque. The turbo might be an equalizer, though.

That's why you see the trend to more and more gears in transmissions and variable speed transmissions. The small engines have to rev to develop the torque.

I recently had an opportunity to drive a turbo 4 Mustang with a paddle shifted 10 speed. If I took control of the trans and dropped it 2 gears below where the computer wanted it, it felt like a small V8 or a V6. Used just as much gas as those engines, too. Let the computer short shift it, like it wanted to, and it was a real dog.