I picked up a mis-boxed flexi fan for my rig one time. It was fine up to about 30 MPH then the temp started to rise. I was standing in front with the hood open scratching my head when the thermostat opened and it began blowing hot air at me. I took the fan and box back to the Auto Parts store and they determined that it was mis-boxed and was reverse rotation. It was a perplexing day.

1951 3800 1-ton
"Earning its keep from the get-go"
In the DITY Gallery
1962 261 (w/cam, Fenton headers, 2 carbs, MSD ign.), SM420 & Brown-Lipe 6231A 3spd aux. trans, stock axles & brakes. Owned since 1971.