Mowing RCK60-27B and RCK60-24B difference??

[eyeeye]

My B2100 came with an RCK54-24B deck And I would like to upsize.
A local guy has an RCK60-27B MMM for sale and I am trying to find out if it will fit my tractor.
Can anyone tell me the differences in the mower decks?
Thanks