Valve cover, for sure. Maybe intake and exhaust will need some spacers to tighten down. I am using an old cj offenhauser intake on my 87 and I had to grindg about 1 1/4" off each bolt hole because the holes where so deep for the long bolts on the cj head. Might be other stuff too, not sure.
I don't feel like working on anything at this time so i sold my yj.