for teh stainless steel it is part number 14298 for dual 3inch outlets and number 14288 for dual 2.5inch outlets. in the regular aluminized(read as much cheaper and sounds teh same) it is number 12298 for dual 3 inch outlets and number 12288 for the dual 2.5 inch outlets. all of these are crossflow style like stock with a 3inch inlet.
go to
www.magnaflow.com for more details.
later
tim