The RB20DET and RB20DE motor was binned if you will during the production run of the R33. Most was due to the weight increase and lack of power for a larger car, and the RB25DE came into its own. The R33 also saw the lost of the RB20DET in the GTS4 version as well.
That changed a bit when the R34 production came out. With new technology Nissan brought back the RB20DE in limited numbers coupled with high volumes of RB25DE motors for the N/A cars.