Best way to find out is to go to JD build it yourself and look at the blade. It will list the quick hitches for the various tractors. I think in this case the blade is interchangable but the quick hitch is different.
Yes it will fit - the only difference is the hoses are longer. I put a hitch and blade on my X485 from a 445 and the only thing needed was a hose extension kit.
Thanks for the reply. Looking at the posts, it looks like you can take a 425 quick hitch and mount it on the X series but can not go backwards? Is there a modification I could do to allow the newer quick hitch fit the 425?