You know these aren't flanged, right?
Summit and Jeg's part numbers are done as follows:
"Vendor code" - "Manufacturer's Part Number"
So those headers are EDL-6550 in Summit. Even if you can't find a part in the catalog, all you need to do is get the vendor code from another product and tack the manufacturer's part number on the end of it.
http://store.summitracing.com/egnsea...s=false&N=+115