PowerPC :: G3 IMac DV 400MHZ With Slot Drive Overclocking

I just restored an old 1999 G3 iMac DV 400MHZ with slot-drive from the dead, and I feel it lacks a bit of power under it's hood. I already put RAM and HDD but the computing power is just not enough. What I want to do is go into OpenFirmware and speed up the cpu and possibly the bus, I remember doing so on my sawtooth but I can't find the code plus that was a G4 and now I have a G3. I also found this page [URL] that shows how to mechanicaly overclock up to 1GHZ but I want to be able to do it non physical if possible. I know this isn't the hot topic now a days but maybe some of you will remember what they used to do and feel some nostalgia(is that a propper word?).