I'm sorry if this is a silly question

The manifold that I bought is from a 132 and as far as I'm aware its from an 1800. After taking off my original 1438 inlet manifold and matching the two together I noticed that the ports on the replacement manifold are smaller than those on my original. My question is shouldn't the 1438 ports be smaller than those of the 1800 ports????
Cheers!