We just switched motors, went from an all steel 406 to an all aluminum 18* motor. Set ride hts and rescaled car, got all our percentages right, now we are spinning and having trouble getting any traction,, car was very good with other motor,, was wondering if the 5th coil could be a concern,, its at 38 inches with 300# spring now,, thats where its always been,, any ideas??