so I don't know how stock you care to be. I went for a double pass rad, and I know they make a triple pass rad. not cores but passes. mine splits on the horizontal and doesn't have a built in cooler because of it. It might give you more cooling capacity.
I agree more testing would help and if your gauge is in question, independent temp readings are in order. but I would run the cheap tests first and see if it makes a difference.