For Pure INT at 90 cap you're much better off with 90 lightning and 90 Ice. 90 Ice for insane snow shield which is godly in PvP. Lightning because the Lightning nukes are much more consistent and powerful than Fire. Here's evidence I found in another topic
My term of comparison was my lv 70 S&S nuker. I had Horse's thunderbolt and compared it to Flame wave Wide and Flame wave burning.
Maybe it's a different story at level 80, but that was what I found. Also, you can see that the damage RANGE of lightning is larger than that of fire.
Here are some facts on the maxed nukes:
Horse's thunderbolt lv 6: 728 - 1352 (300%)-> difference = 624Flame wave Wide lv 13: 780 - 1300 (330%) -> difference = 520
Flame wave Burning lv 18: 709 - 1182 (300%) -> difference = 473.It would make sense that the fire nuke hits more stable at level 80 too, but maybe experience proves otherwise.
Trust LockStar on this one, though. I've been just level 70, whereas he is 80.

EDIT: here are the nuke facts at level 90:
<credits to Konpaku website for this>
Book 5 fire nuke - lv 89: 1028 - 1714 (315%) -> difference = 686
Flame wave wide - lv 90: 1060 - 1766 (330%) -> difference = 706 Level 90 thunderbolt: 989 - 1837 (300%) -> difference = 848 This is where my claim finds support. It might be the other way around effectively in game, but the numbers seem to support what I said. Note that I did not take into account the "%" increases for each nuke. They might just make the difference between how hard the different nukes hit.
Conclusively, only game experience can tell.
