http://www.geocities.com/maddogheaders/
I think you can get them thru Nunzi also. I bought mine used from a local racer, who used them on his 70 Lemans Sport. I paid $375.00, they are Jet Hot coated, and came with the evac setup you see in the pics. All hardware and flanges were included as well. Here is an uncoated set on E-bay for 64-67 GTO.
http://cgi.ebay.com/ebaymotors/ws/eB...tem=7954741348
It says they normally sell for $475.00