Originally Posted by
JohnDThompson
It doesn't "prove" that it's English thread, but given that Bianchi had frames made in Japan as well as Italy, and the Japanese-made frames were English thread, it's likely the OP's frame is a Japanese Bianchi with English thread.
Yes. And sometimes English thread bottom brackets get stripped, and then reamed and re-tapped to Italian thread. And some Italian track frames actually had 65mm wide shells with Italian thread. Shell width at best is only a suggestion of what the shell thread might be.
No. All it would require is using a spindle designed for a 68mm bottom bracket with Italian thread cups. Or, if you have a cartridge bottom bracket, simply letting the non-drive side extend further past the shell than might otherwise be the case.
All of these possibilities do exist but, as I said above, I think any and all are highly improbable. What is most probable is the OP has an English threaded standard road width bottom bracket. Yes, you can make an Italian bottom bracket work in an English shell but, again, I'd bet a fair amount of money that isn't the case here.