The picture of the exhaust manifolds are indeed HI-PO 289...but for a mustang or falcon. The 289 Cobra utilized a tube header exhaust...there is a set for sale for use on a CSX7000 SAI car on ebay...search parts for 7000 series. I think it ends today and it is for $215. This is correct for the 289 Cobra.
the exhaust manifolds shown in the photo will not work in a cobra...the webers will though!
Try this link to the details of the headers on e-bay....
http://cgi.ebay.com/ebaymotors/ws/eB...2865211&rd=1,1