[JC455]

I've got Flowtechs on my 68 LeMans. They fit pretty well (after a few "dimple mods" [img]/infopop/emoticons/icon_wink.gif[/img] ). They have pretty decent ground clearance as well.
For the 74 X body, you really need to use a 67-69 Firebird type of header. These cars are very different from other Pontiacs.
PY was selling some at an excellent price, do a search in this forum.

John