PC2700 isn't DDR-400......PC3200 is
So 200mhz x 2 = 400 with PC3200. But since yours is 2700, 183 x 2 = 366, so it's correct. CPU-Z is right. You're simply mistaken in your assumption, no big deal man.
As for what to set it at, it depends what brand it is, and what timings it is rated for. For example, is it 3-3-3-8? Or 2.5-3-3-3-7? Or 2-3-3-6? etc.......
Find out that info and then someone can help. Although, would also help to know what mobo, just in case.
Info for your 2700/3200: http://en.wikipedia.org/wiki/DDR_SDRAM
Info for your RAM timings:http://en.wikipedia.org/wiki/CAS_Latency
There's more out there, but it gets REALLY technical. Suffice it to say that, generally speaking, lower RAM timings are better. But that means the RAM is better and has to be able to perform at those faster timings. Not all RAM is created equal....just like cars
The best DDR RAM runs around 2-3-3-5 @ 1T.