With a specialized Prototype H/S and TriFan setup, 54watt tec, I was able to get my cel400 to 672mhz....I could get it to 630 passive.....voltages at 672mhz were 2.3
but duckman is right, to go any further than you are right now....is going to get much more costly and much more risky....but hey, if you want more....I cant fault that!
Good luck to ya!
Just a Few Fries Short of a " Happy Meal "!
"HEY! WHO are all you people and WHAT ARE YOU DOING IN MY BATHROOM?"