Mine are the same way! Damnit..I had asked on here before and I was told that they're all the same width. I 'made' mine work. Actually, because the frame rail that connects to it is in two pieces (not a solid u-channel), it will spread out a little. For me, I had to patch that part of the rail and as it happened, it warped almost perfectly to match the support. I'd be interested to know as well if someone else has gotten proper width supports..and who they got them from.