CB500x engine is a plug and play motor. Nothing was different as in the plugs, and even had a 15t counter sprocket which is also what the cbr500r has. Removing and installing engines only took a few hours. Bike is up and running just waiting for my radiator and left middle cowl to come in at my local honda dealer. Then bike will be ready for the road!
The differences in wire harness part numbers and ecu numbers should be specific to the bikes not the engines per say. The cbr and cbx have different tunes and make power in different ways, this would be the big difference in the ecu’s. That said the cbr ecu with the cbr harness on the cbx engine should be just fine. has this been completed? Curious to confirm my thoughts.