mechanical fan mounting studs

What thread size of stud do I need for mounting my mechanical fan blade to the water pump flange ? Is there a kit available ?

Using a 2.375 long aluminum fan spacer, steel fan blade is .25 thick & water pump flange .5 thick so I'm assuming around 4" long ?

I see GM kits which are 5/16" coarse x fine thread studs. Mopar BB440 the same ?

Thanks,

Bolts, not studs!

If you use studs you will have to remove radiator every time you need to take fan off.