It's Alive!!!!!! Today i completed the upgrade by adding a 66.667 Mhz crystal to my PPC so that it now runs at 233 Mhz and everything works fine. The best thing is as i've installed them via 8-DIN sockets should i ever find a 80Mhz crystal i'll be able to up the speed again or if things start getting a little toasty i can downgrade until i get a new heatsink and fan for the PPC. Shiny!!