Since you have an older S-4020 size motor, you will most likely need the Scorpion S-40mm bearing kit V1.0. You will need to disassemble the motor and look at the inner bearings to be sure what size they are. The early version S-4020 motors used a 13x6x5 bearing at the back end of the motor, and a pair of smaller 10x6x3mm bearings stacked on top of one another in the inside of the motor.
If this is the case then the S-40mm Motor Bearing Kit V1.0 is the correct one to get.
On the other hand, if the motor has a 13x6x5 bearing on the inside, and a 13x6x5 on the outside, then the S-40mm Motor Bearing Kit V1.1 is the correct one to get.
Hope that helps!