<VV> Carb Stud Repair advice?

[Grant Young]

While replacing 1964 carbs for a customer, I found that the PO had buggered the mounting for one of the long studs and "repaired" it by drilling a larger hole (not exactly centered) and using a long bolt that goes all the way through the carb mounting boss and installing a nut on the lower end (which requires someone to hold it under the car while tightening said bolt). Would like to replace the stud for the owner and am seeking advice on a quick and easy way to properly repair. Will liquid aluminum hold the stud, or should I install a threaded insert, and if so, what size,
Thanks,
Grant