After running hotter than usual since summer arrived, I had to go back to my old 7-blade Flexlite mech fan. Before switching fans, I did all the preliminary checks and didn't find anything wrong with my thermostat, lower hose, timing, and water flow thru the radiator; although I did find some amount of rust debris. I cleaned and flushed it out. That only left the elec fan. Although its advertised at 2700 cfm, I'm somewhat skeptical of that.
I installed the mech fan and started it up, and immediately could feel the difference in air flow through the radiator. Took it on the freeway, and where I used to run 210-215 degrees, I now run at 175-180, without a shroud. Even at stop lights, it didn't get over 180. But I did stop by by local Mustang shop and picked up the HP 31/2 inch shroud; bolts right on to stock radiator setup with the spacers(sold separately).
BTW, I have the 1 1/2", 2 row, Griffin radiator.