[sharpe 1]

you must change the advance springs that control the movement
of the mechanical advance in the dist. Lighter springs will allow the timing to advance faster. Depending on the cam you are running many engines need to be at full advance about 36 degrees at about 2500 RPMs Bad timing advance could account for your mid range power loss? The curve can be changed in the car, but the best way is to use a dist. machine.