[Bobcat]

Clois ... my experience is just the opposite of yours . On my 427 Galaxie , I went with the BT dual quad to fit the 428 CJ heads and picked up throughout the whole rpm range . Maybe because the Galaxie weighs 4100 lbs or I don`t have as big a cam as you ??
FF2 ... if you use the BT heads , it will raise the exhaust ports up and then you will have to rework your primaries/sidepipes to get them to fit the body .