If it were me, I consider a Lincoln Towncar or Lincoln Mark VIII electric fan, as they are designed for V8s and pull a lot more air than the after market fans. If you want failsafe with two fans and even more cooling capacity, spent a bit more and get a 2009+ F150 electric fan.

All of these come with a shroud, and will need a little bit of trimming. You also can't use a low end controller with them... these pull serious amperage that will melt the controller or blow fuses constantly. You'll need a controller that can handle 40 amps.