Just the bottoms. The frame rots from the bottom up so the top of the frame is actually in great shape. Then you slip the pieces over the remaining good frame and weld it together.
I bought them from Morris, although they were just drop shipped from SafeTCap.
Ahhh, so they are SafeTCaps. I don't think I'd ever seen the full frame rails like that.
Makes sense about the bottoms rotting first. I noticed on my 2005 Rubicon even with a pristine, rust free frame, the ONE area there was rust in was right under the transfer case skid plate where it contacts the frame rails. There was a bunch of rust when I took the stock skid off. Fortunately all it took was 1-hour with the wire wheel and all of the rust came right off once I got it down to bare metal. Either way, that seems to be a very common rust area on TJs.