honestly those temps are perfectly acceptable with the stock heatsink which probably looks like this http://www.google.com.au/imgres?imgurl=http://www.madshrimps.be/files/images/articles/IntelCore2DuoE850045nmWolfdaleCPUReview-massman-21304.jpg&imgrefurl=http://www.madshrimps.be/articles/article/680/Thermalright-Ultra-120-eXtreme-CPU-Cooler-Review/5&usg=__ZWnr0XM-PdfRUTbUFiEbf_fk7Ms=&h=447&w=600&sz=39&hl=en&start=0&zoom=1&tbnid=cShxj8tCYs6oKM:&tbnh=153&tbnw=243&ei=pAfjTbn_DYXIuAPGhozKBg&prev=/search%3Fq%3Dintel%2B%2522core%2B2%2522%2Bheatsink%26hl%3Den%26biw%3D1260%26bih%3D839%26tbm%3Disch&itbs=1&iact=rc&dur=32&page=1&ndsp=23&ved=1t:429,r:1,s:0&tx=139&ty=73. for overclocking you could get a hyper212+ or even a heatsink from a higher end core2 CPU, the ones with the copper core (
http://www.frostytech.com/articleview.cfm?articleid=2132&page=2 )and are much better than the stock e4500 heatsink.