Below are specs from 3 different sources, as well as the dyno results from 289 rebuild done by a magazine. The article focused on engine balancing, and how much horsepower could be gained from a quality, STOCK rebuild. The only thing they did to the engine that was not stock was to install a stock replacement 4bbl intake and an out-of-the-box Carter 625 carb.
The first engine I ever rebuilt was a 289 2bbl in an engine rebuilding class in college. We weren't allowed to add anything that was not stock, or to stock specs. The only difference was that we had bored it .030" over to clean up the cylinders. On the college dyno, it reached 228 horsepower.
I'm not going to invest anymore time proving you wrong, but I shouldn't need to. I'm not sure why you are so convinced the 289 2bbl was so weak, but you should know that if you go around talking like that, you're going to look like an idiot to those in the know. Just some friendly advice.
Take care,
-Chris