Two banks of 8.
I had a similar problem With 2 X 8S batteries I was putting together. I charged each 8S to about 3.55 volts per cel with a BMS and a 15 amp SCC. That had the cells nearly top balanced. I then took them in sets of 4 and top balanced them. I repeated that.
The actual top balance took less than 8 hours per cell instead of 8 days. Charging on the 15 amp SCC took 3 days.