This has been a question in my mind for quite a long time, and I can't help but wonder are all words with stress in their second part pronounced the same all the time? For example, OK, because, etc. I find it a little unusual to say 'That's bi'ka:z' rather than 'That's 'bika:z'. The same is true about 'OK'. Are there any conventions or rules about pronouncing such words? Or are they pronounced always the same way?
P.S. By being pronounced always the same way, I mean, are the words that have stress in the middle (according to dictionaries) always pronounced with stress on the middle part as in because and OK or might they be pronounced with stress on their first part as well?