A lot of different things come into play as which fan will give the best results. A push fan was hard for me to find 30 years ago for a 9u D6. But doing dozer work it seemed a good idea. Without side screens on the engine not sure how much it helped.
Did more farming than dozing with this tractor, the pull fan did more cooling on hot days. After a cold day on the tractor I put the pull fan back on. Get the warm air from engine blown back at you rather than pulling cold air past you. Again in grain stubble in sticky ground more straw got sucked off the tracks than got sucked up from the front with a pull fan.