1. Balanced and Blueprinted.

2. Shot peened rods.

3. Polished beams.

4. Angle cut valve job.

5. Shaved Head.

6. Valve Overlap and Valve lift

7. 3/4 race cam.

8. Jacking up the timing.

9. Blown Motor.

10. Any others you can think of that I for... Login to read more.