Exhaust manifold N2 or N4

What is the difference between an exhaust manifold 3614395 N2 and a 4006741 N4?

From my study on this sight the 3614395 and the 4006741 are the same, but is there a difference between the N4 and N2?

I put a 1977 360 in my 1966 Barracuda. The left side exhaust manifold from the original 273 runs in to the block just under the port. I got a 4006741 N4 but it runs in to the power steering box. I could really use some help on this. Thanks.