IMO I would ADD some timing in low gear and then begin to pull it back on each gear change. Adding timing at the hit will help burn the fuel that accumulates from being on the two step. Further adding timing will help the engine make more power with the lower load it has in first gear and increase efficiency. If it is a three speed I would pull back a couple degrees in second and in high go back to base or where it makes the best MPH. In the end you will have to experiment to find the ideal place for timing to be. Not unusual for timing to be changed from the dyno for many reasons. Increased altitude, moisture in air or two very common reasons. You need to find a curve that accelerates the car the best. That's generally is more down low then up top.