You kninda mixed things up here, is the issue the cat 3 hitch or a 1000 rpm pto?????? Don't quite follow, so hate to advise & steer you wrong.
Do you have a real cat 3 hitch, or is it a cat 3N? The N would be for Narrow, it is set up with cat 3 pin holes, but the width is the same as cat 2. This is very easy to convert with sleeves. Your tractor is at the hp where cat 3N would be more common...
If it is a real cat 3, many tractors have different shims that hold the 3pt arms in different positions, you can rebolt the shims & narrow it down to cat 2 and again use the sleeves on the pins.
As to the pto, your tractor is at the size where it is frequently an option to have 540 pto or 1000 pto by changing a shaft - the pto shaft actually, take out a snap coupler, pull the shaft, & flip it over or insert a different shaft for the other speed.
If that is not an option on your tractor, hum. Running a 540 post hole digger is best at idle to begin with, so you really can't slow down any with the throttle. Guess I would not want to run it off a 1000 rpm tractor, but the adaptor does exsist to try it. I think it would spin too fast for me. Perhaps the maker of the phd offers a 1000 rpm conversion, as cat 2 tractors often have 1000 pto, would make sense to make it compatable with either.
--->Paul
