Best factory exhaust manifolds for small block

I was wondering what were the best factory cast iron small block exhaust manifolds. I am putting together a 318 for best mpg, but am not interested in using headers.

Do you want vintage or do you care? The later 1990's era Magnum manifolds probably flow best but are not as clean/attractive looking as the 1968-71 340 style (which flow pretty decent and look the best IMO).

Prefer vintage-love the look of original.

http://www.moparmusclemagazine.com/techa...t/photo_17.html

Pass side 68-70 340 HP manifold. Drivers side 92-93 mag ex manifold (the early one with the larger outlet). There's a set of em for sale (on here) for $100 + the ride & if I wasn't dead broke right now I'd be all over it.