that's an excellent question and not just for the 9742 but for all coby's. Has anyone overclocked their Coby? let us know and what the stock clock speed was and how much you OC'd it by and what the results were the only android I've OC'd was my virgen moble lg optimus and 600 to 800 mhz is enough to be noticed both in performance and makes a nice hand warmer on cold winter days
I attempted it with a copy of SetCPU but found that the Allwinner CPU became unstable at 1152MHz. At 1190MHz the tablet would bootloop, requiring a reset or nandroid restore through the recovery to fix.
It worked for a while at 1152MHz, then one day the tablet spontaneously rebooted and in the process reset the tablet, wiping all my data and settings. Best I can fathom the kernel panicked as a result of the CPU objecting to being overclocked. So, before it happens to you, stop overclocking.