Maybe.
There are a lot of theories about exhaust design, and lots of different designs that either follow some theory... and plenty that are just bent up to fit and look OK. My belief is that the SOHC4 OEM exhausts were the latter.
I don't know how Bassani developed their design. In the 70s there were probably hundreds of aftermarket exhaust brands available for the Honda fours. Marketing material for most of them touted the amazing power increases that would delight buyers. Bassani, if I remember correctly, was a reputable brand. They still exist making exhausts for the tractor crowd plus some oddball small bikes (... Grom?).
Tuning goals for an exhaust are pretty specific - basically you can get improved low end torque or improved high end horsepower. Getting both seems not to be an option.
But... the header is pretty much the whole shebang as far as power increase goes, and if a factory design is already excellent then there's not much improvement possible unless - with modern bikes - pollution and/or noise control features of the stock system are eliminated.
The muffler mostly just reduces flow by a factor relative to how much noise you can tolerate.
So a Bassani muffler, if designed for your bike's displacement and RPM range and adaptable to your existing header, will probably work OK. How loud it will be... who knows until it's tried? Same with carb changes needed, you have to find that out on your own. I predict it will be louder than stock, and that the carbs will not need jetting changes.
