My 2 cents...
I run a King Kutter 6 foot tiller behind my Cat 2 L5740 with 50 PTO HP.
The tiller specs call for a recommended hp of 35 to 50 on that particular width. I don't think that means that you can't run a more than that because the 48 inch calls for 20 to 35 horsepower and they use the exact same gearbox and gears. I sure it's a power recommendation for good performance of the tiller
I'm sure the gear box and everything else is built to handle more power and the slip clutch is there to take care of the parts anyway.
As far as the hook up, use bushings and go for it I say. I don't know john deere from squat so I can't talk about forward speed and all that. :ashamed: