Did you get a new plug? I found them on Amazon for $8. Used a Dakota digital controller so I have low and high speed function and can program the turn on/off points for both low and high speed. Plus the controller will give you a digital temp readout too. You will like the fan, it fits and works great.
I didn't have to modify anything to mount them. Located where I wanted in front of core, used #14 self drilling sheet metal screws to mount on shroud flange. Perfect fit.