Replace pulley when switching to electric fan?

[Jackson's Dad 64 C10]

We are working on the LY6 that’s going into my son’s ‘64, and I just had a thought. I removed the mechanical fan from the water pump pulley (that was an adventure!), and we are planning on electric fans for a bit of extra clearance. I have searched this a bunch of different ways, but can’t find a good answer... Do I need to swap the water pump pulley out, or is it good to go? I’m not sure if the nut between the fan clutch and the pulley is what retains the pulley, or if it is secured some other way. I obviously don’t want the pulley to come flying off while the engine is running. That would make for a bad day. Thanks for sharing your experience!

Chris