Changing gears

[MiceNReets]

Currently have a ‘16 Zillion Sv 5.5.    No longer need the 5.5 gears (but I’d still hold onto them).  Want to change the gears to a 7 speed.    Do I just change the gear or will I need to change the pinion gear as well?   
 

thanks

[a1712]

Both main and pinion as a set. Brian. 

[MiceNReets]

24 minutes ago, a1712 said:

Both main and pinion as a set. Brian. 

Thanks.