We put a new cdf rotor in our 62 this fall, new helicals in also. We put the spacer bars on thresher end of rotor as dealer recommended. made big improvement in beans but we struggle with broken cobs in corn. Variety of corn with bigger diameter cob is better . Concave clearance helps only so much. Being the rotor diameter is smaller than original one are we breaking cobs between cylinder bars and helicals and if so do i need to add spacer bars full length of rotor. We set the concave to new rotor per dealer instructions.