Yes you can.
The pulleys you get depends on how fast you want to go and what your going to be doing. If you tell me what your going to be doing with the mower and how fast you want to go I can tell you what pulleys to put where.
If you have a hydro transaxle I would not recommend a pulley swap
#4
wjjones
I did, and it helped quite a bit to get the ground speed up to where I wanted it.