you could probably take it up to 200/200 no prob...most people can hit at least 183/183 on the LE's without additional cooling (up from 145 or so)
I put some ramsinks and a bigger cooler on the GPU for my LE and it runs nice and stable at 210/210 and it has the cheaper memory and lower yield proc that your VIVO ;oP
Hope that gives you an idea...
Basically just take it up as high as you can go before you start getting artifacts in extended gameplay and/or benchmarking (3dmark, q3 timedemo, etc..)
Caino