Just like
@ZooMad75 said about his truck and Larry's truck and such, I'm also running a 6.2l radiator and shroud in my V3500 tow rig. And I too am just running a mechanical fan clutch with a big block mechanical fan. I put a 9 blade fan on to try and push as much air as possible and have a 180* thermostat too. All I know is I've towed with that truck a bunch over the last couple years and no matter what have not yet tipped the 200* mark. Even when towing the below setup which was the heaviest I've done with it (and the heaviest it'll probably ever see) at an estimated +/-18k GVRW, the 8.1 liter never got above 195*. So I couldn't be happier with it.
I've always been under the understanding that if you are gonna tow at all with your rig, then a mechanical fan is the only way to go.
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