http://en.community.dell.com/support-forums/desktop/f/3514/t/19329296
6 page thread here on this. Basically no. PentiumD is max. and bigger heatsink needed.800fsb, and 4GB RAM limit also.
Some of the old Pentium4 machines (like the one in my sig.)can get up and go with older Core2Extremes, but this isn't one of them.