I hope it's a really wide truck bed.
I just went through this a week ago. My wife was having some home improvement project done at our house that required them to paint in our garage and they told me I had to move my 03 TJ top so it didn't get paint on it. I thought no problem, I'll just back the GMC under it, lower it down into the bed and be all set. Wrong. It's wider than the box on a 03 GMC. No way to get it in without one side of the top being on the inside of the bed and the other side being outside the bed.