This is a bit puzzling. You cannot use a different rotation fan clutch unless you change the hub pulley assembly. The clutch inside the unit is designed for one direction only. That fan hub you have was not designed for a B series Cummins. Did you turn down the pilot on the hub or increase the pilot in the clutch flange? Cummins hubs and fan clutches should have a 1" pilot. Base 4bt hubs used 4 8mm bolts in a 50mm circle. Industrial hubs used 4 10mm bolts in a 60mm circle. You might check fan hub 922707 which is clockwise but it's not HD. Don't know what the pilot hole size is either. I found a listing for a 4bt hub and fan but don't know if it's the industrial bolt pattern or the standard. Whichever, you would need some smelling salts if you bought one of those as it's over $500 for the clutch assembly and fan blade. Ouch. I checked Uptime Truck Parts and they show an 18 fan blade, but no clutch assembly. Cost wise, you could probably change the hub assembly and pulley to one from a Dodge and use a Dodge fan clutch assembly if the fan isn't too big.
Like I had mentioned earlier, you might consider using a fan hub assembly from a '94-02 Dodge Cummins. It would be the same offset as a standard 4bt hub. Main issue might be the fan blade which is 22" in diameter. Here's a listing on ebay for a complete unit for $200. That's the bracket, pulley, clutch, and fan blade. Not sure how much it extends out from the block compared to what you have now. https://www.ebay.com/itm/Engine-Cooling-Fan-with-Clutch-Bracket-94-02-Dodge-Ram-Cummins-Diesel-5-9/113854755198?hash=item1a8245b17e:g:1wwAAOSwWa5dVY6t:sc:FedExHomeDelivery!28658!US!-1 You could do an electric. Just be sure you have a good fan shroud. Any cooling fan without a shroud isn't very effective.