Let me ask a few questions.

1. Unplug the motor and raise throttle stick. Look and see if the swash is level during the full travel. Is it level?
a. Low stick
b. Mid stick
c. High Stick

2. Did you ensure your servos arm are at 90 degrees at Mid Stick? Subtrim can help with this if you can't do it mechanically.

3. Did you reset all trims and subtrims to zero when you installed the new servos?

4. My first question should have been is this CCPM or Mechanical Mixing?