I used to own a 2920 and I upgraded my turnbuckles to the nice sliding telescoping ones you drop the pin in, Kubota puts on their top of the line tractors...L-Grand Series and to nicer B-series. I have since sold that tractor and put the original ones back on it and transferred these newer ones to my B3200 and have some setting on a shelf somewhere that came with the 3200. Give me 20% of the new price and I will pay the ship. Or if not and you bite the bullet for new get the telescoping ones I have.......so much easier to put the attachments on when you can slide the turnbuckles in and out.
Here is the old thread I used when I converted.
http://www.tractorbynet.com/forums/...92-b7800-b29xx-telescoping-stabilizers-2.html
and here was the shopping list I had from 2013
02174-50160 2 NUT, M16 0.71 $1.42
04011-50120 4 WASHER, PLAIN 0.13 $0.52
04015-60160 2 WASHER, PLAIN 0.32 $0.64
04512-60160 2 WASHER, SPRING 0.19 $0.38
05122-51235 2 PIN, JOINT 1.49 $2.98
05122-61245 2 PIN, JOINT 1.23 $2.46
05511-50425 4 PIN, SPLIT 0.13 $0.52
05515-61000 2 PIN, SNAP 0.45 $0.90
6C070-65310 2 BRACKET,STABILIZER 30.69 $61.38
6C070-65320 2 PIPE, STABILIZER 15.7 $31.40
6C070-65333 2 PLATE, STABILIZER 15.7 $31.40
6C070-65340 2 PIN,STABILIZER 2.6 $5.20
6C070-65350 2 BOLT, STABILIZER 2.6 $5.20
Good luck....With your project.