Those that love their thumbs, I have a backyard full of rocks and other things to pick up and move. Installed on my 447 is the manual positioning thumb with a position locking pin. I have rented the CAT 308 & 312 excavators with impressive buckets and hydraulic thumbs. I love my JD 447, but sure could use a hydraulic thumb. Has anyone gone through the process of installing one on their 447 or 448? If so, could you please share the cost? Thanks!