What Radiator, Shroud and electric fan should I use for my 360?

That little fan is only drawing air through a portion of your radiator and the flow of the fan is probably insufficient as well. A lot of people, including myself, do a dual fan out of a Ford Contour. It has a built in shroud and covers most of the Champion radiator I have. I have it set up where one fan kicks on and a the second kicks on if the temperature gets up around 15 degrees higher. It seems to work well.