273 Exh Port MisMatch

Chit if I know man. Since you've not bothered to post a picture of the offending manifold, I don't even know why I'm trying to help. You think you might can do that? The WHOLE manifold? Then the offending port. A casting number and date code.
Here Ya Go Rusty! I laid on my old back jus' for you man! (I couldn't read the numbers thru the Scale tho)

manifold.jpg

nos.jpg