Radiator fans in cummins swap (W300 School Bus)

[garsard]

Hey everyone, I'm new to the forum and have a question about electric radiator fan capacity.

I've done some searching on the site and read about some other 12 valve cummins swaps and it looks like to keep the intercooler and not chop the firewall (I'd like to avoid that if I can) I'll have to ditch the stock clutch fan and go to electric.

What I haven't found while reading is how well these electric fans can cool your truck. I would like to have enough cooling capacity to tow a small trailer or car behind the bus over steeper grades (I'm from Colorado so being able to go up and over I-70 would make my life easy). Looking to cruise at 65 normally and would like to keep at least 45 or 50 on the grades if that's possible.

If any of you have experience with electric radiator fans or if you've done a cummins swap do you think I could get away with the electric fans or do I need to make room for the stock 5.9 fan

A little bit of info on this vehicle:

1971 W300 nose and chassis with a bus body built by the Superior coach company. Basically firewall forward seems like it's all dodge, all the body rear of the firewall is a school bus. Big tall front, the things shaped like a brick so aero is working against me. Don't know what the weight is but estimate it will weigh 10-12k once loaded.

Originally powered by a 318 but the motor that came in it needed a rebuild and I know a 318 won't have the power I want. I also didn't like the sound of getting 7 or 8 mpg all the time.

Would like to put in a 6bt with a 2wd nv4500 going into the divorced np205. Axles are Dana 70s with 4.88 gears but are going to be regeared to probably a 4.10. I'm switching the tires to 35s, this should get me in a nice comfortable cruising rpm for the cummins


TLDR

Can electric cooling fans properly cool a cummins swapped very un-aerodynamic W300 towing a trailer up steeper grades? Total weight of 15,000-17,000 pounds.

Edit: Grammer

[PwrWgnDrvr]

If u don't want to cut the firewall, u can't have an intercooler, stock radiator, or fan. My electrics never come on, no matter how hot it is, how much Im towing, or if I'm going 90.