General

if i were you, i would try to get higher pdr instead of the extra boss%
boss% is nice but i/ls tend to have higher total damage% than other classes, so their boss dmg% aren't as effective
also, what Grawp77 said, swiftness rune helps a lot so try find one before the jewel phase.
if you can also afford a dsi, that helps even more (on top of swiftness rune+mpe pot)

Thanks guys.

Without the help of any additional pots or buffs, you'll need 2m-2m. Your PDR is fine though since we do our regular damage on Gollux with elemental decrease.

i have around 800k range clean, and I have finished Hellux several times
but i was using lots of pot/ buffs
Guild Skills / MPE potions / Swiss Cheese / Gollux potions / guild blessing / Swiftness Rune
if you know what you are doing and you use this buffs you shouldnt have problems to finish it with 1.2m range
GL

I think except NW pretty much every class needs 2m-2m or close to that. 79% PDR is not enough.