I had a K6-II which I put a big heatsink and large fan on (had to ghetto mod the mounting), sawed a 120mm hole in the case just above the cpu and put another fa

I had a K6-II which I put a big heatsink and large fan on (had to ghetto mod the mounting), sawed a 120mm hole in the case just above the cpu and put another fan there. It overclocked handsomely and stable after that. I don't remember the exact frequencies but I think it was 266MHz stock and clocked close to 400MHz with some modifications.