> This wouldn't work because the chip would still be clocked by 16MHz instead of 25MHz. 
> One thing that MAY work on the IIcx is replacing the christal oscillator by a faster 
> one and replacing the 030 by a version capable of higher speeds. BUT this will only 
> work if the motherboard is also capable of handling the higher speed. This way I 
> upgraded my LCIII from 25Mhz to 33MHz. This works because the LCIII is underrated 
> at 25MHz.
> For the IIcx this may require some soldering to the circuit board though, which is 
> something you may not want to do unless you are very confident that the upgrade will 
> work.

I'd be suspicious at best on a IIcx.  That was the fastest machine apple had at the 
time (ok, second fastest by a hair; the se/30 had no nubus).  I think the faster 030 
chips were available then, so i doubt that apple would have gone with 16 if faster 
would have worked.  

The LC III, however, was positioned in the product line, and it makes sense that parts 
could run faster.

Then again, for about $400, you can get an accellertor with an 040, fpu, cache . . .