vid pad mods are possible but you need the VID of the cpu. always found in coretemp and realtemp, cpuz will display realtime voltage. there are rare instances where i have seen it posted that it shows the VID of the cpu.
knowing the vid is the first step then looking up the settings for that vid, then figuring out what to change the settings too. without seeing the motherboard it is hard to say how much you will want to push the cpu. since dell has the boards designed to operate at a set max TDP. assuming the board can take a quad core then ocing the the dual core with vid pad mods wont be much of a issue. though i still go back to seeing the board is a biggie for me, i dont like seeing ocing on boards with a low count of pwms for the cpu power section. as this will cause problems down the road, as pushing the PWM section section beyond or near its limit will generate alot of heat. generally when the cpu pwm section is pushed to far it could result in programs crashing or windows/system not booting up.
i think as long as you dont go over 1.35v, then you should be ok. i dont think the board would be able to handle much higher with a oc on the cpu as well.