Options are Dutra duals, Hooker, Ausie, Clifford, Mister Twister and I remember seeing a skyward through hood set for derby cars.
http://www.dutra.org/doug/doug-sl6-e...l6-exhaust.htm
http://www.dragtimes.com/parts/New-H...436652567.html
http://www.aussiespeedusa.com/index....chk=1&Itemid=2...