Yes but tricky.  Third party cooler need to use M3 mounting screw in order to fit.  V3681 oem motherboard has no built in back plate, suggesting the stock cooler is directly mounted on M3 standoffs of chassis. [IMAGE]   Disadvantage of third party cooler is unknown fan spec which may throw up a start up bios error if Dell bios finds the fan outside its acceptable rpm range.
Recently Ive been looking into upgrading my Vostro 3681.  Could I upgrade the CPU cooler to a third party name brand one if I ever need to?  Will using a standard third party psu with a 24 pin to 6 pin adapter that claims works with dell motherboards with 6 pin power work. Such as this one: [URL]
Vostro 3681 cooler upgrade, and psu upgrade.