Maybe you can put a 72" finish mower out back. May I ask why you are wanting to do this? This is the only reason I went with the 2520, it is the smallest machine to except the 72" MMM deck. Looks like you will be making an up grade.I know John Deere doesn't recommend it....but that's beside the point....will a 72" mmm deck fit under and match up on 2320 attaching points?