Welcome to the site.
"I have a small John Deere tractor ( 3320 ... 33.4 HP )"
Not as small as you might think around here and the 3320 is 32.5hp and it's PTO is 25hp.
Many folks on tbn like the CCM cylinders. There is a dealer in IL on ebay that sells them as well I believe. Maybe Marion IL area?
Do you have the JD 3rd SVC or the Diverter valve setup at all on your 3320?
Enjoy TBN.