The ruling in the past has been you can't change end bells. By doing so you no longer have the motor you started with.
This came up in onroad a couple of years ago. There was actually a motor on the BRCA list that had an optional endbell approved, and even that wasn't allowed. I didn't agree with that particular ruling, I believed that if it was on the list it should be fine, by the AARCMCC Executive disagreed.
hi Daniel
i need a new end plate for my duo 3 17.5t motor, is it illegal to use the duo 3.5 end plate as this the only one i can get and it is still from the duo series of motors
thanks Christian