Butler runs an after market Solid mount (Rigid) Flex fan on the front that is also just milled off at the bolt mounts to sit back about a quarter of an inch....
BUT...they also take some off the fan shroud to pull more air through the fan and radiator...
You can stand behind a
Butler equipped van and feel the air moving all the way to the back doors....
They are not only trying to cool the van motor, but also cool the entire van all the way back.... (transmission, fuel pump....everything)
I discovered it this Summer.....I had a vibration start to develop on one of my vans and we found the flex fan was starting to wear out (bearing on the fan)....
So, we did a replacement with a temporary fan to run the van...but not the truckmount....
I was told I could have used that different fan...and it would have cooled the van motor just fine....but
Butler did not want me running the
Butler unit with that fan...
They take their R&D serious I am finding to make sure the van is protected while doing the cleaning and you get a lot of durability out of them.