Queen or King side castle for white in Najdorf wit

Hi
As a club player I like the Bc4 in the Najdorf. I am trying to learn this opening systematicaly from the white side. I have reasonable chess knowledge, but I quite confused over the decision to castle Q-side vs K-side. It seems 50-50 for each castling approach, so its far from clear.

Under what conditions should one castle K side vs Q side, alternatively, when wouldnt you castle k side or Q side?

In the Sozin (bishop c4 against najdorf), It seems to me that the most dangerous systems for black are those where white castle kingside, but to give general guidelines in an opening that demande aprecise moveorder is not possible. You will have to studie some lines to know when and where (and of cause why it is so) to place your king.

In the Sozin(Bc4) 0-0 is best option with white king on h1, play f4-5 attacking e6and f7.

As black I would HATE white when he plays O-O since i don't have my Q-side counterattack anymore.