Personally I would look for an older 300, 16hp and all your attachments will fit it. That is assuming that your rear attachments are for a closed frame. If I remember correctly the 317 is an open frame. The KT 17 engines are known to loose oil pressure and burn up bearings on slopes.
https://www.tractordata.com/lawn-tractors/000/0/3/35-john-deere-317.html
https://www.tractordata.com/lawn-tractors/000/0/3/35-john-deere-317.html