Going by replies to this thread in another forum:
BDU-10 AND BDU-21 transmissions - TractorByNet.com
The kit appears to be in the form of a second pump and the mounting parts to add a hydro driven tiller attachment to your model. I've heard of others using power steering pumps. But they are fairly light duty for somewhat intermittent loads. So would depend on what you want to run on it and the flow rate required as to how well it would work.
BDU-10 AND BDU-21 transmissions - TractorByNet.com
The kit appears to be in the form of a second pump and the mounting parts to add a hydro driven tiller attachment to your model. I've heard of others using power steering pumps. But they are fairly light duty for somewhat intermittent loads. So would depend on what you want to run on it and the flow rate required as to how well it would work.