The motor and blower couplers will be different between usage on the 505-515 and the 516-562. The part numbers for these will differ:
#2100 is the suction coupler for models 505-515.
#210056 is the suction coupler for models 516-562.
#2120 is the blower (Emtor) coupler for models 505-515.
#212056 (replaced by the plastic #212059S/212062S) is the blower (Emtor) coupler for models 516-562. #212059S is red plastic, while #212062S is sirocco (tan) plastic.
Hope this helps,
Ben Edge (KirbyClassicIII)
