There was one of those crossmembers on my car when I first got it (68 camaro) and it had gaps too. IIRC it was the inside that fit tight and the outside had a gap which shrunk as you tightened the bolts.
There is nothing wrong with yours in particular.. they all have the gaps from what I have read. I guess CE just made the brackets a bit big so the crossmember could be so interchangable.
http://memimage.cardomain.net/member...30_38_full.jpg