My opinion is that they will only work better pulling the air threw if they are spaced off the radiator and running a cowling, if they are bolted straight to the radiator even in a pulling postion they they are ONLY going to pull air threw the radiator part which the fan covers. In a hilux you don`t have room to run a cowling with the fans spaced off the radiator so I don`t think in a hilux it is going to make any differance if they are pulling or pushing.
If you have room in front to have a cowling and have the fan/s spaced off then they will work the same as cowl and spaced in a pulling postion.
The reason that people think they don`t work as good in a pushing setup is becasue the fans are bolted straight to the rad every time, I have NEVER seen a pushing fan spaced off a radiator and with a cowl between the 2.
Basicly you need to try and make the area that the fan pushes or pulls threw bigger then just the diameter of the fan, this is done by spacing the fan/s away from the radiator and then running a cowling. If the fan is say 100mm away from the radiator (pushing or pulling) and the cowling seals around the outer edge of the fan and runs on an angle out to the outer edge of the radiator and seals around it the air comes threw the fan via a diamiter of say 10inches (250mm) it then is able to spread out while between the fan and rad to an area of say 100 inches (2500mm). Does the same if pulling it just gets to pull from the 100 inches and exit via the 10 inches.
If you look at new cars with elec fans the fans are NEVER bolted straight to the radiator, they are always spaced off it by at least 30 to 40mm and have a cowling.
Hope all this makes sense.
Doesn`t matter if the fan is pushing or pulling it is still moving cold air from the front threw the radiator to the engine bay, the only differance is if pushing the fan blades have cold air on them and when pulling the fan blades have hot air on them and the temp of the fan blades an`t going to do **** with the enginee/water temp.