AS far as I know, 133Mhz is also fine - it's anything above this that is dodgy... GPengine runs at 133 and it hasn;t killed any GP32s yet as far as I know....
The standard version runs at 165Mhz. The 132Mhz version hasn't got as good sound, it's up to you whether you want to risk it - lots of people run the standard version with no problems.
Actually talked to Ph0x, author of the port, few minutes ago. And here is part of the log
...
[23:07] <hando_> btw. any news on scumm progress ?
[23:07] <ph0x_> nothing, no time
[23:08] <hando_> ehh hope you will back to it )
[23:09] <ph0x_> definatelly,when i fidn time
...
Tickle me with a tramp if I'm wrong, but I'm sure that there isn't a 133Mhz version of SCUMM - it's actually 165Mhz... so bear that in mind GP32 lovers