I'd say favor the 98 one. You have enough to get it to level 30.5, CP 3095.
If you were to spend all those candies to power up the 86% one, it would be level 33.5, CP 3209. So, it really wouldn't be that much stronger than the 98% one, and it would be much more expensive to power it up further.
You have already spent 39,000 stardust and 34 candy. It will be 36,000 stardust 32 candy more to reach level 30; it will be 3032 cp with 164 hp.
It will be 75,000 stardust and 66 candy to reach level 30; it will be 3080 cp with 166 hp.
OP said they have 72 Lugia candies already, what else are they going to spend that on. Personally the extra 48cp (3080 vs 3032) would determine if it would be in my top 10 at level 30 or not. Kinda dumb, but this game is equally dumb most of the time***To have the 13/13/13 surpass the 3080 (get to 3083 at level 31) it would take another 8 candy and 10,000 stardust extra. Makes the decision a little closer one.