I have found a JD 4630 that am thinking of buying, i have a loader with mounts that will work on it, the price is right and I just want a second tractor to have around when hauling hay to unload trucks and for other busy times and was woundering if I could switch the 1000 PTO to a 540 like you can with the the JD 4430's?? I think this 4630 came out in 1976, Thanks for any help you can give me?? 101