Maybe I'm confused
If your saying your just putting the rear sleeve hitch on to your existing three point then it's no big deal it will just raise and lower with your deck like stated earlier. If your talking about installing the three point lift with the arm that runs up along the frame and attaches to your lift arm assembly then that should also be doable with the deck lift frame and mule drive in place. Might be tight getting everything bolted up with or without deck frame on. I took your initial post to mean you were installing the 3 point even though you said sleeve hitch ! sorry for any misunderstanding on my part ! good luck either way !
