Here is the full answer. This is what we know:
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Tahnok-Kal originally had Krana Za-Kal until removed by Pohatu and Onua. Bohrok Va then refitted it with an unknown replacement.
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When Toa Nuva reached the Bohrok nest, Bahrag were already awakened and Gahdok says that they have already been touched by Krana-Kal Xa (which is required to do so). We then later see that it was Nuhvok-Kal who possesed the Krana Xa-Kal when it turns silver.
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Kohrak-Kal’s Krana Su-Kal escapes upon its destruction.
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Lehvak-Kal is shown in the online animations to have Krana Vu-Kal, but that is because that model was used for all Bohrok-Kal in those animations. But all the others it was shown for (Kohrak-Kal, Nuhvok-Kal) have their Krana-Kal shown elsewhere, so we can allocate Krana Vu-Kal to Lehvak-Kal.
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We know what the Krana-Kal of Gahlok-Kal was thanks to the Kaita it formed with Lehvak and Kohrak-Kal. The fusion is called Bohrok-Kal Kaita Ja and is said to be piloted by Krana Ja-Kal. Since we already know the Krana-Kal of the other two Bohrok-Kal, the Krana Ja-Kal had to belong to Gahlok-Kal.
[Note: notice the name of the other Bohrok-Kal Kaita Za, supports what we already know of Tahnok-Kal.] -
Lastly, we see two of the Pahrak-Kal’s Krana-Kal, but they are never specified. However since we know the rest, this one is fairly easy to guess. Out of the 8 Krana-Kal 6 of them have abilities which are enhanced versions of their Krana counterparts, analogous to the Kanohi Nuva and Kanohi. But 2 of them have brand new powers specific to the mission of the Bohrok-Kal, namely Xa and Ca. Since Xa-Kal is already with Nuhvok-Kal, the only remaining Krana-Kal to account for is Krana Ca-Kal and that needs to belong to Pahrak-Kal. By the time Za-Kal is captured it reveals the Kal have already located the Bahrag queens - they need Ca-Kal to do so. This is supported by The Official Guide to Bionicle which states that it was indeed Pahrak-Kal who had discovered the Bahrag queens’ location.
So in concluson:
Tahnok-Kal - Krana Za-Kal + unknown second
Nuhvok-Kal - Krana Xa-Kal
Kohrak-Kal - Krana Su-Kal
Lehvak-Kal - Krana Vu-Kal
Pahrak-Kal - Krana Ca-Kal + unknown second
Gahlok-Kal - Krana Ja-Kal + unknown second (more in bonus section)
Here are the pictures of the Krana-Kal we know:
Bonus: Total of three Bohrok-kal had their Krana-Kal removed and replaced by another: Pahrak-Kal, Tahnok-Kal and an unknown third who encountered Boxors mentioned by Nokama (*but based on what we know and chronologically it had to be Gahlok-Kal). By the time all 3 events happened, Bahrag had already been located. The two Krana-Kal not present in the original line up Yo-Kal and Bo-Kal are noticably focused on underground navigation. It is likely that both were included in the three replacement Krana-Kal. The third one was probably Ca-Kal again because it would still be needed to keep track of the Bahrag precise location.
Pahrak-Kal who made the entrance would make good use of the Yo-Kal, Tahnok-Kal as leader would lead with Ca-Kal, and that leaves Gahlok-kal with Bo-Kal for navigation.