all time best (1984 and 5150) came out in 84 and 86. I'd say their earliest days were pre-hair metal. They were more an outgrowth of classic rock of the early 70s, but also clearly inspired by glam.
And really, isn't that basically what the hair metal bands were? guys inspired by early 70s rock, but also inspired by glam? VH is basically proto-hair-metal.