johnklos said:

trag: There are a few ways to get to 40 MHz. The simplest, which is to add a 20 MHz crystal oscillator, seems to work best regardless of VRAM, plus I've seen instances where even faster VRAM doesn't make a difference. Sometimes it's just something on the motherboard which doesn't want to run faster.

For reference, this is how I've done most of them:

http://mail-index.netbsd.org/port-mac68k/2002/05/31/0006.html

Click to expand...

Thank you, John.  I'll have to remember this thread for when I have time to look at the Q605s again.   There were two or three 40MHz speed ups posted on Marc Schrier's site at one time or another.  I don't remember which one I used any more, except  that I did  install the faster clock buffer chip, (MC88916?).  

I've done the 33MHz before without issues.  I have some 20MHz oscillators kicking around somewhere.  I'll have to give that method a try.