I have to be completely honest, you can build a great back.
but to make it goddamn huge, you need deadlifts
i've allways trained my back very hard, yet only since about a year i do deadlifts, and its a massive diffrence.
You can see this easely when comparing strongest man competitors and powerlifters to bodybuilders
the first two, have huge backs that really stand out, while the second, has more defined backs, that are mostly made from growth hormone