</font><font color="blue" class="small">( Is the 47 bh a sub-frame mount? Does it matter? Is there any reason to upgrade to a 48 bh for an extra $1,000? Thanks for the help. What a great site. )</font>
The 47 is NOT a subframe mount. It isn't a 3 point mount, either. Yes it does matter. A subframe can lower ground clearance and interfere with a mid mount mower. A 3 point mount can put too much stress on the tractor. Deere uses RockShaftAssist mounting to attach the 47 (also the 48, 448 and 49 hoes) The tractors were designed for this setup and don't require additional frame components and are rock solid. They go on or off in a jiffy and work wonderfully in place.
the 48 is a bit deeper digger, it also has more reach which can mean less moving the tractor or unload into a higher bed and it can fit the large chassis CUTs. (As far as I can tell the 47 is limited to the mid chassis.) The 48 is being replaced with the 448 which does not list the mid chassis as compatible. I guess there will be a 447 too.
Actually TBN is the GREATEST site!! Glad you found it!