My uncle (by marriage) has a huge dick, I was told by my aunt. So big in fact, that he was embarrassed and ashamed in high school gym class when it was noticed (he's 82 years old now, so that may explain the thinking at the time).
My aunt told me that sex was frequently quite painful and their doctor had given them a rubber donut "cushion" to wear to prevent injury to my aunt.
I also know for a fact that his three sons are also hung huge, as I lived with them awhile when the sons were late teens/early twenties, and there was a lot of bragging and snickering going on, along with a lot of pride in what they had.
Of the three sons, I only saw the youngest son at a nude beach, and he was indeed quite large flaccid. A spontaneous erection I noticed once through his jeans indicated that it was indeed huge. As a guess, probably an easy 8.5 inches. Just a guess.