what headers do you have in mind? there are the Hooker 5208 fenderwells. OT you may or may not have interference at the trans tunnel with a 727 (early A have tolerance issues in some areas but are my favs). Likely the tunnel lip will need to be flattened (best is to grind it off/weld that seam). I would (highly) suggest a 904 but it sounds like you have the eng/trans as a unit or likely it is already in there.