Well, the single fan with no shroud is fine up to about 100 degrees, but higher desert summertime temperatures and the addition of air conditioning are going to require additional cooling capability. My next plan is a full shroud with three Zirgo 9" electric fans (1500cfm each). 

I've started by mocking up the shroud in plastic to determine actual fit. I'm doing this because most metal fabricators work to a tolerance of .125" (or more) and I want .0625" for a tight fit without leaks.

I've taken the mock-up to a metal fabricator to be duplicated in .125" aluminum. There are a variety of aluminum grades, so if you intend to polish your shroud, be certain to purchase the correct grade of aluminum. Got the aluminum shroud back from the fabricator, perfect fit. Now to cut the fan holes and weld on mounts.

Mounts on, fan holes completed, fans mounted.

Installed, left side view                         Top view                           Right side view

Fan wiring harnesses. There are actually three, one still being in the car from the previously mounted Spal Fan. 

Here are the three harnesses mounted to a fiber board that will fit up under the dash. I have power from the battery going into an 80A fused distribution block which feeds into a distribution block that feeds power to the three relays. Each relay is fused between the distribution block and relay with individual 30A fuses. The individual fan power wires are also have 30A in-line fuses. I've fused the ignition hot wires with one 10A fuse. I've also installed a toggle switch under the dash lip that overrides the thermostat sensor sending unit to power the fans should that unit fail.  

Here's the mounting board ready to go under the dash. I replaced the fiberboard with a piece of Lexan plastic that has all mounting holes for the relays and distribution blocks tapped for #8 screws and covered with another piece of Lexan to assure no screws are exposed. 

Wires pulled through dash. I'm going to hardwire the power wires directly to the fans and run the fan ground wires to a common ground. 

Wires attached and bundled.