Well... Now I am not so sure... After posting this, I went searching through the manuals on this site and I found the Estate Keeper 42" Mower Deck manual: http://gardentractor...2-rotary-mower/
In the manual for this attachment, it says:"This unit is shipped complete with all parts required to mount it to your Estate Keeper, with the exception of the drive shaft (B - Fig. 1). This item was supplied with the Model 930 Estate Keeper only. NOTE: The Model 931 Estate Keeper requires drive shaft Model 19313, which must be purchased separately."
So, I'm thinking maybe I need a shorter driveshaft for this then? Where can I get one though? I don't think I have any driveshafts that are any shorter. I found two other driveshafts - one dirty, used one that came off one of my other EK's and another I found in one of my parts boxes that looks almost new and both of these are the exact same length as the driveshaft that in on this tractor right now. I also have another set of attachment mounting arms brand new in one of my parts boxes with the Bolens part number sticker still attached (they aren't even painted yet and are bare metal!), but they are the same length as the mounting arms that I am using to try to mount this mower deck with. I can't seem to find any parts that are different that are for this model of tractor. Very odd...
like Bolens 1000 said all of the drive shafts are the same, all that footnote means is that the model 930 came with the drive shaft and the 931 did not, the drive shaft was an accessory. the 42 inch deck has different arms than the 38 inch as well as the 32 inch. the reel mower, snow caster and the plow attachments all use the same arms as the 32 inch. there are three different arms and one drive shaft. look in the 42 inch deck attachment manual for the part number of the arms that you need.