This might help...
When I bought the school bus to make into a chip truck I didn't check inside the auto transmission to see if there were PTO gears. Ooops...none there so I talked to a transmission shop about adding the gears. SPENDY!
At the time Northern had a store that sold off their returns and seconds at super prices. Some how I stumbled into an auxiliary hydraulic drive.
Quite simple. It came with a big mounting bracket that matched up to the Chevrolet 350 engine. Belt drive exactly like an alternator or AC compressor. It had an electric clutch so it was simple to add a toggle switch onto the dash. I got a switch that lit up red when it was powered and mounted it in the center of the dash over the speedometer. I wired it 'hot' so the engine had to be running to run the pump. More important the red lit switch made sure that the truck wasn't driven with the pump engaged.
I have no clue what the pump output was. I sure didn't need much to run the dual cylinder dump. Speed was not even considered. I do remember that the pump unit wasn't much bigger than the alternator on the Chev 350
All totalled my install only cost a few dollars. I had some surplus hydraulic hoses so I only had to buy the red light switch and the unit at about 80% off list.
