Next, the old conversion has Dexterity 11, which seems way too low to me.
The original flawlessly coordinates two humanoid arms and seven tentacles at the same time, attacking with no penalties.
That doesn't suggest Dex 11 to me!
That degree of multiweapon coordination is on par with a Marilith, which has Dex 19.
Just because whoever designed the 3E Kraken decided to give it Dex 10 (which makes no sense to me) doesn't mean we have to make the Krakentua as clumsy.
I'd rather have it be Dex 17 like a Giant Squid, which feels way more reasonable.
Constitution we've already decided on.
Intelligence can stay 17, the same as the original monster.
Wisdom is bizarrely high.
Why does the old version give females Wis 27 and males Wis 25? I don't see anything in the description to suggest they're particularly sagacious or perceptive. Indeed, they are arrogant tyrants, which isn't a personality often associated with wisdom! The don't need it to make up for a poor base saving throw, since Aberrations have good Will saves.
I'd cut those numbers down to something more modest, although I haven't decided how modest yet.
Charisma should be good. I'm OK with the current figures. Would be happy to bump the male up to 20 to match a standard Kraken and maybe even giving the female 24 or we can leave them as is.
That'd add up to be something like this:
Female: Str 35, Dex 17, Con 33, Int 17, Wis 16 [or 18?], Cha 22 [or 24?]
Male: Str 35, Dex 17, Con 24, Int 17, Wis 16 [or 18?], Cha 18 [or 20?]
I could see the female being the next Strength modifier up from the Male and would be OK giving them a higher Wisdom modifier too, perhaps:
Female #2: Str 37 or 36, Dex 17, Con 32, Int 17, Wis 20 or 21, Cha 22 [or 24?]
Male #2: Str 34 or 35, Dex 17, Con 24, Int 17, Wis 19 or 18, Cha 18 [or 20?]
The above also nudges the female's Constitution down to 32 to make them half-odd half-evens.
EDIT: Come to think of it, a regular Kraken is four-even two-odd, so keeping the female Con 33 would make her two-odd four-odd. That has a pleasant symmetry, so maybe:
Female #2a: Str 37 or 36, Dex 17, Con 33, Int 17, Wis 20 or 21, Cha 22 [or 24?]
Male #2a: Str 34 or 35, Dex 17, Con 24, Int 17, Wis 19 or 18, Cha 19 [or 21?]