I can confirm that the new Holley/Hooker ,"Blackheart" mid length headers in stainless steel fit absolutely perfect in a 69 Firebird w/ 2004 GTO LS-1. I also have their reccomended engine mounts. Very impressed.

Tim john---

Wish i could run the full holley setup, but i cannot do it with the gto accessories that are required for my blower setup