The complete motors are interchangeable in the frame, so any model NSR motor will fit any other model's frame (i.e. MC16 complete motor will fit into an MC28 frame).

All NSR motors share external dimensions & mounting points. Just make sure the relevant electronic components are used for the chassis the motor is fitted to. (This isn't a "be-all and end-all" recipe, just a safe setting - there are circumstances where components are mixed such as with the MC21 F3 setup where a PGM-II is utilised.)

Andy.
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