Greetings. There's a lot of talk on here about 3.7's getting their stock throttle body ported and also the manifold as well. If you port your throttle body and manifold to both match 73mm, or you buy a BBK 73mm body and port your manifold, I don't imagine there would be any noticeable difference between the two, airflow would be identical.
So you might be able to get your stock TB and Manifold ported at the same time and not have to buy a new part at all. I went ahead and bought the BBK 73mm throttle body though. I'm not biased to it, it's just what I wanted.
Buying a 73mm throttle body means, that I still have my stock one (unchanged) sitting in my tool shed, where the rest of my stock parts are (should for some reason, I ever need to return it to stock). Since I live in California
, I chose not to physically modify my stock components.