I D needed on these 340 manifolds please.
Found this on the exhost....
I assume the 6 referenced is what looks like a 3 or an 8 in your photo.
4006741 exhaust manifold.
400
6741 is a 72-74 318 a-body left/driver side manifold, should fit your 70 Duster but the price sounds kind of high to me for a 318 exhaust manifold, maybe if they were both 360 ones, would be nice to have a matched set on a 340