after running the ran with those cheap zip ties that went through the radiator for 3 years and eventually springing a leak from the friction of the fan on the fins, it was time to get a new radiator and a REAL mount for the fan.
lowe's.... 28x24" 16 gauge sheet metal $35
lowe's.... 4 x 1/4" x 1.5" long 28 TPI allen bolts w/nuts
lowe's.... 6 14mm self tapping screws (should have used nuts and bolts but i was lazy)
cut sheet metal 18" x 23 3/4" w/ fancy plasma cutter
lay fan centered on sheet metal. trace with sharpie.
drill 4 holes for bolts that will hold fan to sheet metal.
find something round to trace with the plasma so air can flow through the fan blades (had a viper flywheel handy that was the perfect size)
plasma circle in sheet metal
paint (i used rubberized undercoating from car quest)
bolt fan to sheet metal.
use your angle grinder to cut the bolts flush with the end of the nuts so they don't go through the radiator and cause a leak
lay down the fan and shroud on the radiator and self tap three screws in each side (note there are holes in the radiator so don't waste a screw going through one of those)
sorry no pics of the process, i was busy making it... not thinking of taking pictures.
it pulls air across the entire radiator and held my temps down steady at 180 degrees ALL DAY saturday while wheeling up in the mountains.
-Erik <--- using a 16" Imperial fan from advance auto parts ($70)